LeanMapper\Result::extractIds PHP Method

    private function extractIds($column)
    {
        if ($this->isAlias($column)) {
            $column = $this->trimAlias($column);
        }
        $ids = [];
        foreach ($this->data as $data) {
            if (!isset($data[$column]) or $data[$column] === null) {
                continue;
            }
            $ids[$data[$column]] = true;
        }
        return array_keys($ids);
    }