/// <summary>
/// Gets the single CLR resource identifier for the given CLR resource type.
/// </summary>
/// <remarks>
/// The CLR based resource identifier can come from either a json:api resource object or
/// a resource identifier.
/// </remarks>
/// <typeparam name="TResource">Type of CLR resource to find.</typeparam>
/// <typeparam name="TResourceId">Type of CLR resource identifier.</typeparam>
/// <returns>Returns the single CLR resource identifier if it exists, null otherwise.</returns>
/// <exception cref="DocumentReadException">Is thrown if there are
/// multiple CLR resource identifiers for the given CLR resource type.</exception>
public static TResourceId GetResourceId <TResource, TResourceId>(this IDocumentReader documentReader)
where TResource : class, IResource
{
Contract.Requires(documentReader != null);
var clrResourceType = typeof(TResource);
var clrResourceId = documentReader.GetResourceId <TResourceId>(clrResourceType);
return(clrResourceId);
}