Telerik Grid Page size, page index and need datasource events

In telerik grid, we have to just give data source

 protected void radGridAppeals_PageIndexChanged(object sender, GridPageChangedEventArgs e)

        {

            

            this.radGridAppeals.DataSource = FilteredAppealList;

        }

               protected void radGridAppeals_PageSizeChanged(object sender, GridPageSizeChangedEventArgs e)

        {

            

            this.radGridAppeals.DataSource = FilteredAppealList;

        }

Also we dont need to add e.new page size or e.newpageindex And we also need virtualitemcount may be

OR we can use NeedDataSource instead of the above functions

        protected void radGridAppeals_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)

        {

            this.radGridAppeals.DataSource = FilteredAppealList;

        }