docs: protected <T> ResponseEntity<T> sendRequest(
              String pathFragment,
              HttpMethod method,
              List<? extends NameValuePair> getParams,
              Object postData,
              Class<T> returnType) {
          HttpHeaders headers = new HttpHeaders();
          headers.add(XAPI_VERSION_HEADER, XAPI_VERSION_VALUE);
  
          // make multipart data is handled correctly.
          if (postData instanceof MultiValueMap) {
              headers.setContentType(MediaType.MULTIPART_FORM_DATA);
          }
  
          URI fullURI = buildRequestURI(pathFragment, getParams);
  
          HttpEntity<?> entity = new HttpEntity<>(postData, headers);
          ResponseEntity<T> response = restTemplate.exchange(fullURI, method, entity, returnType);
  
          return response;
      }