code: protected void doPostForm(String path, MultivaluedMap<String, String> formParams, MultivaluedMap<String, String> headers) throws ClientException {
          this.readLock.lock();
          try {
              WebResource.Builder requestBuilder = getResourceWrapper().rewritten(path, HttpMethod.POST).getRequestBuilder();
              ensurePostFormHeaders(headers, requestBuilder, true, false);
              ClientResponse response = requestBuilder.post(ClientResponse.class);
              errorIfStatusNotEqualTo(response, ClientResponse.Status.OK, ClientResponse.Status.NO_CONTENT);
              response.close();
          } catch (ClientHandlerException ex) {
              throw new ClientException(ClientResponse.Status.INTERNAL_SERVER_ERROR, ex.getMessage());
          } finally {
              this.readLock.unlock();
          }
      }
docs: Submits a form.
  
  @param path the API to call.
  @param formParams the multi-part form content.
  @param headers any headers to send. If no Content Type header is
  specified, it adds a Content Type for form data.
  
  @throws ClientException if a status code other than 200 (OK) and 204 (No
  Content) is returned.