public IQ(IqType type, Jid from, Jid to)
     : this()
 {
     this.Type   = type;
     this.From   = from;
     this.To     = to;
 }

		public AvatarIq(IqType type) : this()
		{			
			this.Type = type;		
		}

 public PrivacyIq(IqType type, Jid to)
     : this(type)
 {
     To = to;
 }

 public PrivateIq(IqType type, Jid to, Jid from)
     : this(type, to)
 {
     this.From = from;
 }

		/// <summary>
		/// Performs an IQ set/get request asynchronously and optionally invokes a
		/// callback method when the IQ response comes in.
		/// </summary>
		/// <param name="type">The type of the request. This must be either
		/// IqType.Set or IqType.Get.</param>
		/// <param name="to">The JID of the intended recipient for the stanza.</param>
		/// <param name="from">The JID of the sender.</param>
		/// <param name="data">he content of the stanza.</param>
		/// <param name="language">The language of the XML character data of
		/// the stanza.</param>
		/// <param name="callback">A callback method which is invoked once the
		/// IQ response from the server comes in.</param>
		/// <returns>The ID value of the pending IQ stanza request.</returns>
		/// <exception cref="ArgumentException">The type parameter is not IqType.Set
		/// or IqType.Get.</exception>
		/// <exception cref="ObjectDisposedException">The XmppCore object has been
		/// disposed.</exception>
		/// <exception cref="InvalidOperationException">The XmppCore instance is not
		/// connected to a remote host.</exception>
		/// <exception cref="IOException">There was a failure while writing to the
		/// network.</exception>
		public string IqRequestAsync(IqType type, Jid to = null, Jid from = null,
			XmlElement data = null, CultureInfo language = null,
			Action<string, Iq> callback = null) {
			AssertValid();
			return IqRequestAsync(new Iq(type, null, to, from, data, language), callback);
		}

 public VersionIq(IqType type, Jid to, Jid from)
     : this(type, to)
 {
     this.From = from;
 }

 public StorageIq(IqType type, Jid to, Jid from)
     : this(type, to)
 {
     this.From = from;
 }

 public AuthIq(IqType type, Jid to, Jid from)
     : this(type, to)
 {
     this.From = from;
 }

 public BrowseIq(IqType type, Jid to) : this(type)
 {
     To = to;
 }

 public PubSubIq(IqType type)
     : this()
 {
     this.Type = type;
 }

		/// <summary>
		/// Performs an IQ set/get request and blocks until the response IQ comes in.
		/// </summary>
		/// <param name="type">The type of the request. This must be either
		/// IqType.Set or IqType.Get.</param>
		/// <param name="to">The JID of the intended recipient for the stanza.</param>
		/// <param name="from">The JID of the sender.</param>
		/// <param name="data">he content of the stanza.</param>
		/// <param name="language">The language of the XML character data of
		/// the stanza.</param>
		/// <param name="millisecondsTimeout">The number of milliseconds to wait
		/// for the arrival of the IQ response or -1 to wait indefinitely.</param>
		/// <returns>The IQ response sent by the server.</returns>
		/// <exception cref="ArgumentException">The type parameter is not
		/// IqType.Set or IqType.Get.</exception>
		/// <exception cref="ArgumentOutOfRangeException">The value of millisecondsTimeout
		/// is a negative number other than -1, which represents an indefinite
		/// timeout.</exception>
		/// <exception cref="ObjectDisposedException">The XmppCore object has been
		/// disposed.</exception>
		/// <exception cref="InvalidOperationException">The XmppCore instance is not
		/// connected to a remote host.</exception>
		/// <exception cref="IOException">There was a failure while writing to the
		/// network, or there was a failure reading from the network.</exception>
		/// <exception cref="TimeoutException">A timeout was specified and it
		/// expired.</exception>
		public Iq IqRequest(IqType type, Jid to = null, Jid from = null,
			XmlElement data = null, CultureInfo language = null,
			int millisecondsTimeout = -1) {
			AssertValid();
			return IqRequest(new Iq(type, null, to, from, data, language), millisecondsTimeout);
		}

		/// <summary>
		/// Sends an IQ response for the IQ request with the specified id.
		/// </summary>
		/// <param name="type">The type of the response. This must be either
		/// IqType.Result or IqType.Error.</param>
		/// <param name="id">The id of the IQ request.</param>
		/// <param name="to">The JID of the intended recipient for the stanza.</param>
		/// <param name="from">The JID of the sender.</param>
		/// <param name="data">he content of the stanza.</param>
		/// <param name="language">The language of the XML character data of
		/// the stanza.</param>
		/// <exception cref="ArgumentException">The type parameter is not IqType.Result
		/// or IqType.Error.</exception>
		/// <exception cref="ObjectDisposedException">The XmppCore object has been
		/// disposed.</exception>
		/// <exception cref="InvalidOperationException">The XmppCore instance is not
		/// connected to a remote host.</exception>
		/// <exception cref="IOException">There was a failure while writing to the
		/// network.</exception>
		public void IqResponse(IqType type, string id, Jid to = null, Jid from = null,
			XmlElement data = null, CultureInfo language = null) {
			AssertValid();
			IqResponse(new Iq(type, id, to, from, data, null));
		}

 public FeatureNegIq(IqType type)
     : this()
 {
     this.Type = type;
 }

 public BindIq(IqType type)
     : this()
 {
     Type = type;
 }