code: private function execute(AbstractRequestTransport $requestTransport, $responseType)
      {
          $response = $this->apiTransport->send(
              $requestTransport->getPath(),
              $requestTransport->getMethod(),
              $requestTransport->getQueryParams(),
              json_encode($requestTransport->getBody()),
              $requestTransport->getHeaders()
          );
  
          if ($response->getStatusCode() != 200) {
              $this->processError($response); // throw ResponseException
          }
  
          $responseData = json_decode($response->getBody(), true);
  
          if (!$responseData) {
              throw new JsonParseException('Decode response error', json_last_error());
          }
  
          return ResponseCreator::create($responseType, $responseData);
      }
docs: @param AbstractRequestTransport $requestTransport
  @param string                   $responseType
  
  @return AbstractResponse
  
  @throws ResponseException
  @throws TransportException
  @throws ResponseParseException
  @throws JsonParseException