### Question:
GenericServiceTaskEditorWidget extends Composite implements HasValue<GenericServiceTaskValue> { protected void onChange() { GenericServiceTaskValue newValue = new GenericServiceTaskValue(); newValue.setServiceOperation(serviceOperation.getValue()); newValue.setServiceInterface(serviceInterface.getValue()); newValue.setServiceImplementation(implementation.getValue()); setValue(newValue, true); }  @PostConstruct void init(); void setServiceImplementationOptions(List<String> options); void setReadOnly(boolean readOnly); @Override GenericServiceTaskValue getValue(); @Override void setValue(GenericServiceTaskValue value); @Override void setValue(GenericServiceTaskValue newValue, boolean fireEvents); @Override HandlerRegistration addValueChangeHandler(ValueChangeHandler<GenericServiceTaskValue> handler);  }### Answer:
@Test public void onChange() { widget.onChange(); verify(widget, times(1)).setValue(any(GenericServiceTaskValue.class), any(boolean.class)); }