How to set the content based column width when merge cell applied in WPF DataGrid (SfDataGrid)?

this.dataGrid.GridColumnSizer = new GridColumnSizerExt();public class GridColumnSizerExt : GridColumnSizer
{
 
        public GridColumnSizerExt()
        {
 
        }
 
        protected override Size GetCellSize(Size rect, GridColumn column, object data, GridQueryBounds bounds)
        {
            //return empty size for merged cell
            var rowIndex = this.DataGrid.ResolveToRowIndex(data);
            var columnIndex = DataGrid.Columns.IndexOf(column);
            var covererdCellInfo = this.DataGrid.CoveredCells.GetCoveredCellInfo(rowIndex, columnIndex);
            if (covererdCellInfo != null)
                return Size.Empty;
            return base.GetCellSize(rect, column, data, bounds);
        }
}

private void SfDataGrid_OnQueryCoveredRange(object sender, GridQueryCoveredRangeEventArgs e)
{
            //merge the columns in a row by setting the column range using Left and Right properties of CoveredCellInfo.
            if (e.RowColumnIndex.RowIndex == 3)
            {
                e.Range = new CoveredCellInfo(0, 2, 3, 3);
                e.Handled = true;
            }
 
            //Refresh the autosize calculation after the merge cell operation performed in SfDataGrid
            this.dataGrid.GridColumnSizer.ResetAutoCalculationforAllColumns();
            this.dataGrid.GridColumnSizer.Refresh();
}