protected function makeSearchableFields(Collection $fields = null, $tableName)
    {
        if (is_null($fields))
        {
            return '';
        }

        $searchables = [];

        foreach ($fields as $field)
        {
            if (intval($field->search_priority) > 0)
            {
                $searchables[] = "'{$tableName}.{$field->name}' => {$field->search_priority}";
            }
        }

        return implode(",", $searchables);
    }