/**
  * Marshal a command and dispatch it to its appropriate handler.
  *
  * @param mixed $command
  * @param \ArrayAccess $source
  * @param array $extras
  * @return mixed 
  * @static 
  */
 public static function dispatchFrom($command, $source, $extras = array())
 {
     return \Collective\Bus\Dispatcher::dispatchFrom($command, $source, $extras);
 }