@Test
public void testFilterWithNull() {

    // Insert a null entry into the dataset
    DataSet expensesDataSet = clientDataSetManager.getDataSet(EXPENSES);
    int column = expensesDataSet.getColumnIndex(expensesDataSet.getColumnById(COLUMN_DEPARTMENT));
    expensesDataSet.setValueAt(0, column, null);
    // Draw the charts
    displayerCoordinator.drawAll();
    // Click on the "Engineering" slice
    reset(listener);
    deptPieChart.filterUpdate(COLUMN_DEPARTMENT, 1);
    // Check the allRowsTable receives the filter request
    DataSet dataSet = allRowsTable.getDataSetHandler().getLastDataSet();
    verify(listener, never()).onError(any(Displayer.class), any(ClientRuntimeError.class));
    verify(listener).onDataLookup(allRowsTable);
    verify(listener).onRedraw(allRowsTable);
    assertEquals(dataSet.getRowCount(), 18);
}