code: public Response postQuery(final String system, final InputStream input, final String resource,
          final HttpHeaders httpHeaders) {
  
          final JaxRx impl = Systems.getInstance(system);
          final Document doc = new SchemaChecker("post").check(input);
          final Map<QueryParameter, String> param = getParameters(doc, impl);
          final ResourcePath path = new ResourcePath(resource, param, httpHeaders);
          return createResponse(impl, path);
      }
docs: This method will be called when a HTTP client sends a POST request to an
  existing resource with 'application/query+xml' as Content-Type.
  
  @param system
  The implementation system.
  @param input
  The input stream.
  @param resource
  The resource
  @param httpHeaders
  HTTP header attributes.
  @return The {@link Response} which can be empty when no response is
  expected. Otherwise it holds the response XML file.