private function invokeCallback($method_name, $must_exist=true)
	{
		return static::table()->callback->invoke($this,$method_name,$must_exist);
	}
private function invokeCallback($method_name, $must_exist=true)
	{
		return static::table()->callback->invoke($this,$method_name,$must_exist);
	}
private function invokeCallback ( $ method_name , $ must_exist = true ) { return static :: table ( ) -> callback -> invoke ( $ this , $ method_name , $ must_exist ) ; }
Invokes the specified callback on this model.

@param string $method_name Name of the call back to run.
@param boolean $must_exist Set to true to raise an exception if the callback does not exist.
@return boolean True if invoked or null if not
Invokes the specified callback on this model .