Trying to create "groupby" for the modules for Api V8

While trying to create “groupby” feature for the api v8 of suitecrm api I have been getting an error.

{
“errors”: {
“status”: 400,
“title”: null,
“detail”: “Option Api\V8\Param\Options\GroupBy does not exist!”
}
}

But I have created a file named GroupBy.php in the Param/Options

GroupBy.php have a class named GroupBy