original_string: public function logout()
      {
          if (is_null($userId = $this->getUserId())) {
              return null;
          }
  
          return $this->leave(static::USER_PREFIX . $userId);
      }
code: public function logout()
      {
          if (is_null($userId = $this->getUserId())) {
              return null;
          }
  
          return $this->leave(static::USER_PREFIX . $userId);
      }
code_tokens: public function logout ( ) { if ( is_null ( $ userId = $ this -> getUserId ( ) ) ) { return null ; } return $ this -> leave ( static :: USER_PREFIX . $ userId ) ; }
docstring: Logout with current sender's fd.
  
  @return mixed
docstring_tokens: Logout with current sender s fd .