protected function getDuplicatesByField($field)
    {
        $duplicates = DataList::create(self::class)
            ->filter(
                [
                    $field   => $this->$field,
                    'BlogID' => (int) $this->BlogID
                ]
            );

        if ($this->ID) {
            $duplicates = $duplicates->exclude('ID', $this->ID);
        }

        return $duplicates;
    }