code: public function hasChildController($controllerName)
      {
          $methodName = $this->parseControllerName($controllerName);
          return $this->reflection->hasMethod($methodName);
      }
docs: Check if the named controller exists as a child of this controller.
  
  Takes the requested child controller name and checks for a corresponding
  class method name. (Note: The class method will end with the word
  Controller)
  
  @param $controllerName
  @return bool