public function canBeJoined($possible = null)
    {
        if ($possible !== null) {
            deprecationWarning(
                'Using EagerLoadable::canBeJoined() as a setter is deprecated. ' .
                'Use setCanBeJoined() instead.'
            );
            $this->setCanBeJoined($possible);
        }

        return $this->_canBeJoined;
    }