// Get an IGrouping object.
IGrouping<System.Reflection.MemberTypes, System.Reflection.MemberInfo> group =
    typeof(String).GetMembers().
    GroupBy(member => member.MemberType).
    First();

// Output the key of the IGrouping, then iterate
// through each value in the sequence of values
// of the IGrouping and output its Name property.
Console.WriteLine("\nValues that have the key '{0}':", group.Key);
foreach (System.Reflection.MemberInfo mi in group)
    Console.WriteLine(mi.Name);

// The output is similar to:

// Values that have the key 'Method':
// get_Chars
// get_Length
// IndexOf
// IndexOfAny
// LastIndexOf
// LastIndexOfAny
// Insert
// Replace
// Replace
// Remove
// Join
// Join
// Equals
// Equals
// Equals
// ...