@Test
public void testExecute() throws Exception {

    final String var = "test";
    final Block block = createBlock();
    final Clear clear = block.appendChild(Clear.class);
    clear.setNamelist(var);
    final DataModel model = getDataModel();
    Mockito.when(model.existsVariable(var)).thenReturn(true);
    ClearStrategy strategy = new ClearStrategy();
    try {
        executeTagStrategy(clear, strategy);
    } catch (JVoiceXMLEvent e) {
        Assert.fail(e.getMessage());
    }
    Mockito.verify(model).updateVariable(var, null);
}