Elastica\Query\Ids::addType PHP Method

    public function addType($type)
    {
        if ($type instanceof ElasticaType) {
            $type = $type->getName();
        } elseif (empty($type) && !is_numeric($type)) {
            // A type can be 0, but cannot be empty
            return $this;
        }
        $this->_params['type'][] = $type;
        return $this;
    }