/**
  * Adds an argument to pass to the service constructor/factory method.
  *
  * @param mixed $argument An argument
  *
  * @return ehough_iconic_Definition The current instance
  *
  * @api
  */
 public function addArgument($argument)
 {
     $this->_delegate->addArgument($argument);
     return parent::addArgument($argument);
 }