public bool Cancel( string messageId )
{
if( string.IsNullOrEmpty( messageId ) )
throw new ArgumentNullException( ExceptionMessage.NULL_MESSAGE_ID );
return Invoker.InvokeSync<bool>( MESSAGING_MANAGER_SERVER_ALIAS, "cancel",
new Object[] { Backendless.AppId, Backendless.VersionNum, messageId } );
}