public function addConditions($lefts, $rights, $operators = array())
    {
        if (count($lefts) != count($rights)) {
            throw new PropelException("Unable to create join because the left column count isn't equal to the right column count");
        }
        foreach ($lefts as $key => $left) {
            $this->addCondition($left, $rights[$key], isset($operators[$key]) ? $operators[$key] : self::EQUAL);
        }
    }