Purl\Url::set PHP Метод

    public function set($key, $value)
    {
        $this->initialize();
        $this->data[$key] = $this->preparePartValue($key, $value);
        return $this;
    }

 /**
  * Return an instance with the specified user information.
  *
  * This method MUST retain the state of the current instance, and return
  * an instance that contains the specified user information.
  *
  * Password is optional, but the user information MUST include the
  * user; an empty string for the user is equivalent to removing user
  * information.
  *
  * @param string $user The user name to use for authority.
  * @param null|string $password The password associated with $user.
  * @return self A new instance with the specified user information.
  */
 public function withUserInfo($user, $password = null)
 {
     $uriAsString = $this->uriAsString;
     $url = new Url($uriAsString);
     if (empty($user)) {
         $url->set('user', null);
         $url->set('pass', null);
     } else {
         $url->set('user', $user);
         $url->set('pass', $password);
     }
     return new self($url->getUrl());
 }