/**
  * @return TokenResponse
  */
 public function send()
 {
     $url = $this->serverConfig->getParams()['token_endpoint'];
     $params = [['name' => 'grant_type', 'contents' => self::GRANT_TYPE], ['name' => 'refresh_token', 'contents' => $this->refreshToken]];
     $response = $this->httpClient->request('POST', $url, ['multipart' => $params]);
     return new TokenResponse($response);
 }
 /**
  * @return TokenResponse
  */
 public function send()
 {
     $url = $this->serverConfig->getParams()['token_endpoint'];
     $response = $this->httpClient->request('POST', $url, ['multipart' => $this->getParams()]);
     return new TokenResponse($response);
 }