code: public function getInterfaces()
      {
          $reflection = new ReflectionClass($this->interface);
          if ($reflection->isInterface()) {
              return array($this->interface);
          }
  
          return $this->onlyParents($reflection->getInterfaces());
      }
docs: Gets the list of interfaces from a class.
  If the class name is actually an interface then just that interface is returned.
  
  @returns array          List of interfaces.