Pinq\Iterators\Standard\FilterIterator::doFetch PHP Метод

    protected function doFetch()
    {
        $filter = $this->filter;
        while ($element = $this->iterator->fetch()) {
            $keyCopy = $element[0];
            $valueCopy = $element[1];
            if ($filter($valueCopy, $keyCopy)) {
                return $element;
            }
        }
    }