code: public function get(OAuthConsumerInterface $consumer,
                          OAuthTokenInterface $token,
                          $httpverb,
                          $url,
                          $params = [])
      {
          uksort($params, 'strcmp');
  
          $base_url = $this->baseURL($httpverb, $url, $params);
          $key = $consumer->secret.'&'.$token->secret;
  
          return base64_encode(hash_hmac('sha1', $base_url, $key, true));
      }
docs: Get a signature for the request.
  
  @param OAuthConsumerInterface $consumer
  @param OAuthTokenInterface    $token
  @param string                 $httpverb
  @param string                 $url
  @param array                  $params
  
  @return string