/// <summary>
        /// Returns the first 24 photos for a given tag cluster.
        /// </summary>
        /// <param name="tag">The tag whose cluster photos you want to return.</param>
        /// <param name="clusterId">The cluster id for the cluster you want to return the photos. This is the first three subtags of the tag cluster appended with hyphens ('-').</param>
        /// <param name="extras">Extra information to return with each photo.</param>
        /// <returns></returns>
        public PhotoCollection TagsGetClusterPhotos(string tag, string clusterId, PhotoSearchExtras extras)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.tags.getClusterPhotos");
            parameters.Add("tag", tag);
            parameters.Add("cluster_id", clusterId);
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            return GetResponseCache<PhotoCollection>(parameters);
        }

        /// <summary>
        /// Returns the first 24 photos for a given tag cluster.
        /// </summary>
        /// <param name="tag">The tag whose cluster photos you want to return.</param>
        /// <param name="clusterId">The cluster id for the cluster you want to return the photos. This is the first three subtags of the tag cluster appended with hyphens ('-').</param>
        /// <param name="extras">Extra information to return with each photo.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void TagsGetClusterPhotosAsync(string tag, string clusterId, PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.tags.getClusterPhotos");
            parameters.Add("tag", tag);
            parameters.Add("cluster_id", clusterId);
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }

        /// <summary>
        /// Gets a list of photos for the given panda.
        /// </summary>
        /// <param name="pandaName">The name of the panda to return photos for.</param>
        /// <param name="extras">The extras to return with the photos.</param>
        /// <param name="perPage">The number of photos to return per page.</param>
        /// <param name="page">The age to return.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void PandaGetPhotosAsync(string pandaName, PhotoSearchExtras extras, int page, int perPage, Action<FlickrResult<PandaPhotoCollection>> callback)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.panda.getPhotos");
            parameters.Add("panda_name", pandaName);
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));

            GetResponseAsync<PandaPhotoCollection>(parameters, callback);
        }

        /// <summary>
        /// Gets a list of photos for the given panda.
        /// </summary>
        /// <param name="pandaName">The name of the panda to return photos for.</param>
        /// <param name="extras">The extras to return with the photos.</param>
        /// <param name="perPage">The number of photos to return per page.</param>
        /// <param name="page">The age to return.</param>
        /// <returns>A list of photos for the panda.</returns>
        public PandaPhotoCollection PandaGetPhotos(string pandaName, PhotoSearchExtras extras, int page, int perPage)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.panda.getPhotos");
            parameters.Add("panda_name", pandaName);
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));

            return GetResponseCache<PandaPhotoCollection>(parameters);
        }

        /// <summary>
        /// Get the next and previous favorites in a users list of favorites, based on one of their favorites.
        /// </summary>
        /// <param name="photoId">The photo id of the photo for which to find the next and previous favorites.</param>
        /// <param name="userId">The user id of the users whose favorites you wish to search.</param>
        /// <param name="numPrevious">The number of previous favorites to list. Defaults to 1.</param>
        /// <param name="numNext">The number of next favorites to list. Defaults to 1.</param>
        /// <param name="extras">Any extras to return for each photo in the previous and next list.</param>
        /// <returns></returns>
        public FavoriteContext FavoritesGetContext(string photoId, string userId, int numPrevious, int numNext, PhotoSearchExtras extras)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.favorites.getContext");
            parameters.Add("user_id", userId);
            parameters.Add("photo_id", photoId);
            parameters.Add("num_prev", Math.Max(1, numPrevious).ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            parameters.Add("num_next", Math.Max(1, numNext).ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            return GetResponseCache<FavoriteContext>(parameters);
        }

        /// <summary>
        /// Get the next and previous favorites in a users list of favorites, based on one of their favorites.
        /// </summary>
        /// <param name="photoId">The photo id of the photo for which to find the next and previous favorites.</param>
        /// <param name="userId">The user id of the users whose favorites you wish to search.</param>
        /// <param name="numPrevious">The number of previous favorites to list. Defaults to 1.</param>
        /// <param name="numNext">The number of next favorites to list. Defaults to 1.</param>
        /// <param name="extras">Any extras to return for each photo in the previous and next list.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        /// <returns></returns>
        public void FavoritesGetContextAsync(string photoId, string userId, int numPrevious, int numNext, PhotoSearchExtras extras, Action<FlickrResult<FavoriteContext>> callback)
        {
            var parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.favorites.getContext");
            parameters.Add("user_id", userId);
            parameters.Add("photo_id", photoId);
            parameters.Add("num_prev", Math.Max(1, numPrevious).ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            parameters.Add("num_next", Math.Max(1, numNext).ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<FavoriteContext>(parameters, callback);
        }

        /// <summary>
        /// Gets a list of photos from the most recent interstingness list.
        /// </summary>
        /// <param name="date">The date to return the interestingness photos for.</param>
        /// <param name="extras">The extra parameters to return along with the search results.
        /// See <see cref="PhotoSearchOptions"/> for more details.</param>
        /// <param name="perPage">The number of results to return per page.</param>
        /// <param name="page">The page of the results to return.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void InterestingnessGetListAsync(DateTime date, PhotoSearchExtras extras, int page, int perPage, Action<FlickrResult<PhotoCollection>> callback)
        {
            var parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.interestingness.getList");

            if (date > DateTime.MinValue) parameters.Add("date", date.ToString("yyyy-MM-dd", System.Globalization.DateTimeFormatInfo.InvariantInfo));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (extras != PhotoSearchExtras.None)
                parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }

        /// <summary>
        /// Gets a list of photos from the most recent interstingness list.
        /// </summary>
        /// <param name="date">The date to return the interestingness photos for.</param>
        /// <param name="extras">The extra parameters to return along with the search results.
        /// See <see cref="PhotoSearchOptions"/> for more details.</param>
        /// <param name="perPage">The number of results to return per page.</param>
        /// <param name="page">The page of the results to return.</param>
        /// <returns></returns>
        public PhotoCollection InterestingnessGetList(DateTime date, PhotoSearchExtras extras, int page, int perPage)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.interestingness.getList");

            if (date > DateTime.MinValue) parameters.Add("date", date.ToString("yyyy-MM-dd", System.Globalization.DateTimeFormatInfo.InvariantInfo));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (extras != PhotoSearchExtras.None)
                parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            return GetResponseCache<PhotoCollection>(parameters);
        }

		/// <summary>
		/// Utility method to convert the <see cref="PhotoSearchExtras"/> enum to a string.
		/// </summary>
		/// <example>
		/// <code>
        ///     PhotoSearchExtras extras = PhotoSearchExtras.DateTaken &amp; PhotoSearchExtras.IconServer;
		///     string val = Utils.ExtrasToString(extras);
		///     Console.WriteLine(val);
        /// </code>
        /// outputs: "date_taken,icon_server";
		/// </example>
		/// <param name="extras"></param>
        /// <returns></returns>
		public static string ExtrasToString(PhotoSearchExtras extras)
		{
			System.Text.StringBuilder sb = new System.Text.StringBuilder();
			if( (extras & PhotoSearchExtras.DateTaken) == PhotoSearchExtras.DateTaken )
				sb.Append("date_taken");
			if( (extras & PhotoSearchExtras.DateUploaded) == PhotoSearchExtras.DateUploaded )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("date_upload");
			}
			if( (extras & PhotoSearchExtras.IconServer) == PhotoSearchExtras.IconServer )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("icon_server");
			}
			if( (extras & PhotoSearchExtras.License) == PhotoSearchExtras.License )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("license");
			}
			if( (extras & PhotoSearchExtras.OwnerName) == PhotoSearchExtras.OwnerName )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("owner_name");
			}
			if( (extras & PhotoSearchExtras.OriginalFormat) == PhotoSearchExtras.OriginalFormat )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("original_format");
			}

			if( (extras & PhotoSearchExtras.LastUpdated) == PhotoSearchExtras.LastUpdated )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("last_update");
			}

			if( (extras & PhotoSearchExtras.Tags) == PhotoSearchExtras.Tags )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("tags");
			}

			if( (extras & PhotoSearchExtras.Geo) == PhotoSearchExtras.Geo )
			{
				if( sb.Length>0 ) sb.Append(",");
				sb.Append("geo");
			}

			return sb.ToString();
		}

        /// <summary>
        /// Returns a list of the latest public photos uploaded to flickr.
        /// </summary>
        /// <param name="extras">A comma-delimited list of extra information to fetch for each returned record.</param>
        /// <param name="page">The page of results to return. If this argument is omitted, it defaults to 1.</param>
        /// <param name="perPage">Number of photos to return per page. If this argument is omitted, it defaults to 100. The maximum allowed value is 500.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void PhotosGetRecentAsync(int page, int perPage, PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.photos.getRecent");
            parameters.Add("api_key", apiKey);
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }

        /// <summary>
        /// Gets a list of a users photos which are not in a set.
        /// </summary>
        /// <param name="perPage">Number of photos per page.</param>
        /// <param name="page">The page number to return.</param>
        /// <param name="extras"><see cref="PhotoSearchExtras"/> enumeration.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void PhotosGetNotInSetAsync(int page, int perPage, PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
        {
            PartialSearchOptions options = new PartialSearchOptions();
            options.PerPage = perPage;
            options.Page = page;
            options.Extras = extras;

            PhotosGetNotInSetAsync(options, callback);
        }

        /// <summary>
        /// Gets the public photos for given users ID's contacts.
        /// </summary>
        /// <param name="userId">The user ID whose contacts you wish to get photos for.</param>
        /// <param name="count">The number of photos to return. Defaults to 10, maximum is 50.</param>
        /// <param name="justFriends">True to just return photos from friends and family (excluding regular contacts).</param>
        /// <param name="singlePhoto">True to return just a single photo for each contact.</param>
        /// <param name="includeSelf">True to include photos from the user ID specified as well.</param>
        /// <param name="extras">A list of extra details to return for each photo.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void PhotosGetContactsPublicPhotosAsync(string userId, int count, bool justFriends, bool singlePhoto, bool includeSelf, PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.photos.getContactsPublicPhotos");
            parameters.Add("api_key", apiKey);
            parameters.Add("user_id", userId);
            if (count > 0) parameters.Add("count", count.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (justFriends) parameters.Add("just_friends", "1");
            if (singlePhoto) parameters.Add("single_photo", "1");
            if (includeSelf) parameters.Add("include_self", "1");
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }

 /// <summary>
 /// Return the list of photos belonging to your contacts that have been commented on recently.
 /// </summary>
 /// <param name="dateLastComment">Limits the resultset to photos that have been commented on since this date. The default, and maximum, offset is (1) hour.</param>
 /// <param name="extras"></param>
 /// <param name="page">The page of results to return. If this argument is omitted, it defaults to 1.</param>
 /// <param name="perPage">Number of photos to return per page. If this argument is omitted, it defaults to 100. The maximum allowed value is 500.</param>
 /// <returns></returns>
 public PhotoCollection PhotosCommentsGetRecentForContacts(DateTime dateLastComment, PhotoSearchExtras extras, int page, int perPage)
 {
     return PhotosCommentsGetRecentForContacts(dateLastComment, null, extras, page, perPage);
 }

 /// <summary>
 /// Return a list of your photos that have been recently created or which have been recently modified.
 /// Recently modified may mean that the photo's metadata (title, description, tags)
 /// may have been changed or a comment has been added (or just modified somehow :-)
 /// </summary>
 /// <param name="minDate">The date from which modifications should be compared.</param>
 /// <param name="extras">A list of extra information to fetch for each returned record.</param>
 /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
 public void PhotosRecentlyUpdatedAsync(DateTime minDate, PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
 {
     PhotosRecentlyUpdatedAsync(minDate, extras, 0, 0, callback);
 }

        /// <summary>
        /// Utility method to convert the <see cref="PhotoSearchExtras"/> enum to a string.
        /// </summary>
        /// <example>
        /// <code>
        ///     PhotoSearchExtras extras = PhotoSearchExtras.DateTaken &amp; PhotoSearchExtras.IconServer;
        ///     string val = Utils.ExtrasToString(extras);
        ///     Console.WriteLine(val);
        /// </code>
        /// outputs: "date_taken,icon_server";
        /// </example>
        /// <param name="extras"></param>
        /// <returns></returns>
        public static string ExtrasToString(PhotoSearchExtras extras)
        {
            List<string> extraList = new List<string>();

            if ((extras & PhotoSearchExtras.DateTaken) == PhotoSearchExtras.DateTaken) extraList.Add("date_taken");
            if ((extras & PhotoSearchExtras.DateUploaded) == PhotoSearchExtras.DateUploaded) extraList.Add("date_upload");
            if ((extras & PhotoSearchExtras.IconServer) == PhotoSearchExtras.IconServer) extraList.Add("icon_server");
            if ((extras & PhotoSearchExtras.License) == PhotoSearchExtras.License) extraList.Add("license");
            if ((extras & PhotoSearchExtras.OwnerName) == PhotoSearchExtras.OwnerName) extraList.Add("owner_name");
            if ((extras & PhotoSearchExtras.OriginalFormat) == PhotoSearchExtras.OriginalFormat) extraList.Add("original_format");
            if ((extras & PhotoSearchExtras.LastUpdated) == PhotoSearchExtras.LastUpdated) extraList.Add("last_update");
            if ((extras & PhotoSearchExtras.Tags) == PhotoSearchExtras.Tags) extraList.Add("tags");
            if ((extras & PhotoSearchExtras.Geo) == PhotoSearchExtras.Geo) extraList.Add("geo");
            if ((extras & PhotoSearchExtras.MachineTags) == PhotoSearchExtras.MachineTags) extraList.Add("machine_tags");
            if ((extras & PhotoSearchExtras.OriginalDimensions) == PhotoSearchExtras.OriginalDimensions) extraList.Add("o_dims");
            if ((extras & PhotoSearchExtras.Views) == PhotoSearchExtras.Views) extraList.Add("views");
            if ((extras & PhotoSearchExtras.Media) == PhotoSearchExtras.Media) extraList.Add("media");
            if ((extras & PhotoSearchExtras.PathAlias) == PhotoSearchExtras.PathAlias) extraList.Add("path_alias");
            if ((extras & PhotoSearchExtras.SquareUrl) == PhotoSearchExtras.SquareUrl) extraList.Add("url_sq");
            if ((extras & PhotoSearchExtras.ThumbnailUrl) == PhotoSearchExtras.ThumbnailUrl) extraList.Add("url_t");
            if ((extras & PhotoSearchExtras.SmallUrl) == PhotoSearchExtras.SmallUrl) extraList.Add("url_s");
            if ((extras & PhotoSearchExtras.MediumUrl) == PhotoSearchExtras.MediumUrl) extraList.Add("url_m");
            if ((extras & PhotoSearchExtras.Medium640Url) == PhotoSearchExtras.Medium640Url) extraList.Add("url_z");
            if ((extras & PhotoSearchExtras.LargeSquareUrl) == PhotoSearchExtras.LargeSquareUrl) extraList.Add("url_q");
            if ((extras & PhotoSearchExtras.Small320Url) == PhotoSearchExtras.Small320Url) extraList.Add("url_n");
            if ((extras & PhotoSearchExtras.LargeUrl) == PhotoSearchExtras.LargeUrl) extraList.Add("url_l");
            if ((extras & PhotoSearchExtras.OriginalUrl) == PhotoSearchExtras.OriginalUrl) extraList.Add("url_o");
            if ((extras & PhotoSearchExtras.Description) == PhotoSearchExtras.Description) extraList.Add("description");
            if ((extras & PhotoSearchExtras.Usage) == PhotoSearchExtras.Usage) extraList.Add("usage");
            if ((extras & PhotoSearchExtras.Visibility) == PhotoSearchExtras.Visibility) extraList.Add("visibility");
            if ((extras & PhotoSearchExtras.Rotation) == PhotoSearchExtras.Rotation) extraList.Add("rotation");

            return String.Join(",", extraList.ToArray());
        }

        /// <summary>
        /// Return the list of photos belonging to your contacts that have been commented on recently.
        /// </summary>
        /// <param name="dateLastComment">Limits the resultset to photos that have been commented on since this date. The default, and maximum, offset is (1) hour.</param>
        /// <param name="contactsFilter">A list of contact NSIDs to limit the scope of the query to.</param>
        /// <param name="extras"></param>
        /// <param name="page">The page of results to return. If this argument is omitted, it defaults to 1.</param>
        /// <param name="perPage">Number of photos to return per page. If this argument is omitted, it defaults to 100. The maximum allowed value is 500.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void PhotosCommentsGetRecentForContactsAsync(DateTime dateLastComment, string[] contactsFilter, PhotoSearchExtras extras, int page, int perPage, Action<FlickrResult<PhotoCollection>> callback)
        {
            CheckRequiresAuthentication();

            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.photos.comments.getRecentForContacts");
            if (dateLastComment != DateTime.MinValue) parameters.Add("date_lastcomment", UtilityMethods.DateToUnixTimestamp(dateLastComment));
            if (contactsFilter != null && contactsFilter.Length > 0) parameters.Add("contacts_filter", String.Join(",", contactsFilter));
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }

        /// <summary>
        /// Gets a list of photos for a given group.
        /// </summary>
        /// <param name="groupId">The group ID for the group.</param>
        /// <param name="tags">Space seperated list of tags that photos returned must have.
        /// Currently only supports 1 tag at a time.</param>
        /// <param name="userId">The group member to return photos for.</param>
        /// <param name="extras">The <see cref="PhotoSearchExtras"/> specifying which extras to return. All other overloads default to returning all extras.</param>
        /// <param name="perPage">The number of photos per page.</param>
        /// <param name="page">The page to return.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        public void GroupsPoolsGetPhotosAsync(string groupId, string tags, string userId, PhotoSearchExtras extras, int page, int perPage, Action<FlickrResult<PhotoCollection>> callback)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.groups.pools.getPhotos");
            parameters.Add("group_id", groupId);
            if (tags != null && tags.Length > 0) parameters.Add("tags", tags);
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (userId != null && userId.Length > 0) parameters.Add("user_id", userId);
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }

 /// <summary>
 /// Returns a list of your photos with no tags.
 /// </summary>
 /// <param name="extras">A comma-delimited list of extra information to fetch for each returned record.</param>
 /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
 public void PhotosGetUntaggedAsync(PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
 {
     PhotosGetUntaggedAsync(0, 0, extras, callback);
 }

        /// <summary>
        /// Gets a collection of photos for a photoset.
        /// </summary>
        /// <param name="photosetId">The ID of the photoset to return photos for.</param>
        /// <param name="extras">The extras to return for each photo.</param>
        /// <param name="privacyFilter">The privacy filter to search on.</param>
        /// <param name="page">The page to return, defaults to 1.</param>
        /// <param name="perPage">The number of photos to return per page.</param>
        /// <param name="media">Filter on the type of media.</param>
        /// <returns>An array of <see cref="Photo"/> instances.</returns>
        public PhotosetPhotoCollection PhotosetsGetPhotos(string photosetId, PhotoSearchExtras extras, PrivacyFilter privacyFilter, int page, int perPage, MediaType media)
        {
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.photosets.getPhotos");
            parameters.Add("photoset_id", photosetId);
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));
            if (privacyFilter != PrivacyFilter.None) parameters.Add("privacy_filter", privacyFilter.ToString("d"));
            if (page > 0) parameters.Add("page", page.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (perPage > 0) parameters.Add("per_page", perPage.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (media != MediaType.None) parameters.Add("media", (media == MediaType.All ? "all" : (media == MediaType.Photos ? "photos" : (media == MediaType.Videos ? "videos" : String.Empty))));

            return GetResponseCache<PhotosetPhotoCollection>(parameters);
        }

        /// <summary>
        /// Gets your contacts most recent photos.
        /// </summary>
        /// <param name="count">The number of photos to return, from between 10 and 50.</param>
        /// <param name="justFriends">If true only returns photos from contacts marked as
        /// 'friends'.</param>
        /// <param name="singlePhoto">If true only returns a single photo for each of your contacts.
        /// Ignores the count if this is true.</param>
        /// <param name="includeSelf">If true includes yourself in the group of people to 
        /// return photos for.</param>
        /// <param name="extras">Optional extras that can be returned by this call.</param>
        /// <param name="callback">Callback method to call upon return of the response from Flickr.</param>
        /// <exception cref="ArgumentOutOfRangeException">
        /// Throws a <see cref="ArgumentOutOfRangeException"/> exception if the cound
        /// is not between 10 and 50, or 0.</exception>
        public void PhotosGetContactsPhotosAsync(int count, bool justFriends, bool singlePhoto, bool includeSelf, PhotoSearchExtras extras, Action<FlickrResult<PhotoCollection>> callback)
        {
            CheckRequiresAuthentication();

            if (count != 0 && (count < 10 || count > 50) && !singlePhoto)
            {
                throw new ArgumentOutOfRangeException("count", String.Format(System.Globalization.CultureInfo.InvariantCulture, "Count must be between 10 and 50. ({0})", count));
            }
            Dictionary<string, string> parameters = new Dictionary<string, string>();
            parameters.Add("method", "flickr.photos.getContactsPhotos");
            if (count > 0 && !singlePhoto) parameters.Add("count", count.ToString(System.Globalization.NumberFormatInfo.InvariantInfo));
            if (justFriends) parameters.Add("just_friends", "1");
            if (singlePhoto) parameters.Add("single_photo", "1");
            if (includeSelf) parameters.Add("include_self", "1");
            if (extras != PhotoSearchExtras.None) parameters.Add("extras", UtilityMethods.ExtrasToString(extras));

            GetResponseAsync<PhotoCollection>(parameters, callback);
        }