/**
  * Adds new child validator.
  * 
  * @param      AgaviValidator The new child validator.
  *
  * @author     Uwe Mesecke <*****@*****.**>
  * @since      0.11.0
  */
 public function addChild(AgaviValidator $validator)
 {
     $name = $validator->getName();
     if (isset($this->children[$name])) {
         throw new InvalidArgumentException('A validator with the name "' . $name . '" already exists');
     }
     $this->children[$name] = $validator;
     $validator->setParentContainer($this);
 }