gistfile1.php

<?php

public function findSubscribers(Query $query, $options)
    {

        $query
            ->contain([
                'UserSettings' => function ($q) {
                    return $q->where(['UserSettings.id' => UserSetting::ALERTS]);
                }
            ])
            ->matching('Roles', function  ($q){
                return $q->where(['Roles.id' => UserRole::BUYING]);
            })->map(function ($user){
                $var = '';
                return 1;
            });

        return $query;
    }