How to reject the changes made in the WinForms GridGroupingControl?

private void btn_reject_Click(object sender, EventArgs e)
{
    DataTable dt = this.gridGroupingControl1.DataSource as DataTable;
    //Rolls back all the changes made to the table since it was loaded or after the AcceptChanges() was called.
    dt.RejectChanges();
}
private void btn_accept_Click(object sender, EventArgs e)
{
    DataTable dt = this.gridGroupingControl1.DataSource as DataTable;
    //Commits all the changes made to the table.
    dt.AcceptChanges();
}

Private Sub btn_reject_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As DataTable = TryCast(Me.gridGroupingControl1.DataSource, DataTable)
    'Rolls back all the changes made to the table since it was loaded or after the AcceptChanges() was called.
    dt.RejectChanges()
End Sub
Private Sub btn_accept_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As DataTable = TryCast(Me.gridGroupingControl1.DataSource, DataTable)
    'Commits all the changes made to the table.
    dt.AcceptChanges()
End Sub