function get_user_groups($user_id) { // retrieve user groups from database $groups = array('Editors', 'Moderators', 'Subscribers'); return $groups; } // example usage $user_groups = get_user_groups($user_id);In the example, we define a function called `get_user_groups` which returns an array of user groups. We simulate retrieving the user groups from a database, but in reality, it could be retrieved from any source such as a text file or an API. The example usage demonstrates how we can call the `get_user_groups` function and assign the returned array to a variable, `$user_groups`. It is difficult to determine the specific package or library used with this function as it is a basic functionality provided by PHP itself. However, in a larger project, this function may be part of a custom class or library.