src/FelixOnline/Base/BaseManager.php
public function group($group)
    {
        if (!is_array($group)) {
            $this->group = array($group);
        } else {
            $this->group = $group;
        }

        return $this;
    }
public function group($group)
    {
        if (!is_array($group)) {
            $this->group = array($group);
        } else {
            $this->group = $group;
        }

        return $this;
    }
Add grouping to query