### Question:
VariableListItemWidgetViewImpl implements VariableListItemWidgetView,
                                                       ComboBoxView.ModelPresenter { @EventHandler("deleteButton") public void handleDeleteButton(final ClickEvent e) { parentWidget.removeVariable(getModel()); }  Set<String> getTagSet(); void setTagSet(Set<String> tagSet); String getPreviousCustomValue(); void setPreviousCustomValue(String previousCustomValue); void setParentWidget(final VariablesEditorWidgetView.Presenter parentWidget); @Override void setTextBoxModelValue(final TextBox textBox,
                                     final String value); @Override void setListBoxModelValue(final ValueListBox<String> listBox,
                                     final String value); @Override String getModelValue(final ValueListBox<String> listBox); @PostConstruct void init(); @Override VariableRow getModel(); @Override void setModel(final VariableRow model); @Override VariableType getVariableType(); @Override String getDataTypeDisplayName(); @Override void setDataTypeDisplayName(final String dataTypeDisplayName); @Override String getCustomDataType(); @Override void setCustomDataType(final String customDataType); @Override void setCustomTags(final List<String> tags); @Override List<String> getCustomTags(); @Override void setDataTypes(final ListBoxValues dataTypeListBoxValues); @Override void setTagTypes(final List<String> tagTypes); @Override void setReadOnly(final boolean readOnly); @EventHandler("deleteButton") void handleDeleteButton(final ClickEvent e); @EventHandler("closeButton") void handleCloseButton(final ClickEvent e); @EventHandler("acceptButton") void handleAcceptButton(final ClickEvent e); @Override void notifyModelChanged(); @Override void setTagsNotEnabled();  }### Answer:
@Test public void testHandleDeleteButton() { VariableRow model = mock(VariableRow.class); when(view.getModel()).thenReturn(model); view.setParentWidget(parent); view.handleDeleteButton(null); verify(parent).removeVariable(model); }