code: public function getInterfaceMethods()
      {
          $methods = array();
          $interfaces = $this->getInterfaces();
          foreach ($interfaces as $interface) {
              $methods = array_merge($methods, get_class_methods($interface));
          }
  
          return array_unique($methods);
      }
docs: Gets the list of methods for the implemented interfaces only.
  
  @returns array      List of enforced method signatures.