Method: Adds “Opt in” or “Opt out” link to the main “Plugins” page link actions collection.
Method: Checks if given API result is a non-empty and not an error object.
Method: Checks if given API result is a non-empty entity object with non-empty ID.
Method: Make sure a given argument is an array of a specific type.
Method: Send a JSON response back to an Ajax request, indicating failure.