PdfGridColumnCollection constructor
      
      PdfGridColumnCollection(
    
- PdfGrid grid
Initializes a new instance of the PdfGridColumnCollection class with the parent grid.
Implementation
PdfGridColumnCollection(PdfGrid grid) {
  _helper = PdfGridColumnCollectionHelper(this);
  _helper._grid = grid;
  _helper._columns = <PdfGridColumn>[];
  _helper._columnsWidth = -1;
}