[Angular] How to add serial number in ng-grid

Problem
If I would like to add serial number in ng-grid, how to do it?
I would like to implement in client side instead of server side.

The column configuration in ng-grid is as bellows:

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$scope.tab4.synonymCols = [{ field : 'value', displayName : 'value', cellClass : 'text-left', width : '25%' }, { field : 'synonyms', displayName : 'synonyms', cellClass : 'text-left', width : '70%' } ];

How-To
The updated column configuration in ng-grid is as bellows:

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$scope.tab4.synonymCols = [{ field : 'seq', displayName : 'no', cellClass : 'text-left', width : '5%', cellTemplate: '<div class="ngCellText ng-scope col1 colt1" ng-class="col.colIndex()"><span ng-cell-text="">{{row.rowIndex + 1}}</span></div>' }, { field : 'value', displayName : 'value', cellClass : 'text-left', width : '25%' }, { field : 'synonyms', displayName : 'synonyms', cellClass : 'text-left', width : '70%' } ];