Msieprawski\ResourceTable\Helpers\Column::index PHP Method

    public function index()
    {
        return $this->_data['index'];
    }

 /**
  * Checks if provided order configuration (from GET) is valid
  *
  * @param array $params
  * @return bool
  */
 private function _validSort(array $params)
 {
     if (!isset($params['order_by']) || !isset($params['order_dir'])) {
         return false;
     }
     if (!in_array(strtoupper($params['order_dir']), ['ASC', 'DESC'])) {
         return false;
     }
     foreach ($this->_columns as $data) {
         $column = new Column($data);
         if ($column->index() == $params['order_by']) {
             return true;
         }
     }
     return false;
 }