protected function getPolicyColumn(Model $model)
    {

        $connection = $model->getConnection();
        $table      = $connection->getTablePrefix() . $model->getTable();
        $schema     = $connection->getDoctrineSchemaManager($table);
        $columns    = Cache::remember('keys_' . $table, 30, function() use($model) {
                    return Schema::getColumnListing($model->getTable());
                });


        $column = null;
        foreach (self::$patternedColumns as $name) {
            if (!is_null($column)) {
                break;
            }
            $column = array_search($name, $columns) !== false ? $name : null;
        }
        if (is_null($column)) {
            foreach ($schema->listTableForeignKeys($table) as $foreignKeyConstraint) {
                if ($foreignKeyConstraint->getForeignTableName() !== 'tbl_users') {
                    continue;
                }
                $column = current($foreignKeyConstraint->getLocalColumns());
            }
        }

        return $column;
    }