/// <summary>
/// Tests if a string is empty
/// </summary>
/// <param name="continuation"></param>
public static void Empty(this IBe <string> continuation)
{
continuation.Empty(NULL_STRING);
}
/// <summary>
/// Tests if a string is empty, with a provided custom error message
/// </summary>
/// <param name="continuation">Continuation to operate on</param>
/// <param name="customMessage">Custom message to include when failing</param>
public static void Empty(
this IBe <string> continuation,
string customMessage)
{
continuation.Empty(() => customMessage);
}