api_params[:order] = @orderby_spec if @orderby_spec
api_params[:filters] = @filters if @filters
res = arvados_api_client.api @resource_class, '', api_params
api_params[:order] = @orderby_spec if @orderby_spec
api_params[:filters] = @filters if @filters
res = arvados_api_client.api @resource_class, '', api_params