function heightHasChanged() {
                var newViewPortHeight = renderBodyContainer.getViewportHeight();

                if (newViewPortHeight !== viewportHeight) {
                  viewportHeight = newViewPortHeight;
                  return true;
                }
                return false;
              }
@ngdoc object
 @name ui.grid.emptyBaseLayer.directive:uiGridEmptyBaseLayer
 @description Shows empty rows in the background of the ui-grid, these span
 the full height of the ui-grid, so that there won't be blank space below the shown rows.
 @example
 <pre>
 <div ui-grid="gridOptions" class="grid" ui-grid-empty-base-layer></div>
 </pre>
 Or you can enable/disable it dynamically by passing in true or false. It doesn't
 the value, so it would only be set on initial render.
 <pre>
 <div ui-grid="gridOptions" class="grid" ui-grid-empty-base-layer="false"></div>
 </pre>