### Question:
IntegerBox implements IsWidget,
                                   HasValue<Long> { public void setId(String id) { view.setId(id); } @Inject  IntegerBox(IntegerBoxView view); @Override Long getValue(); @Override void setValue(Long value); @Override void setValue(Long value,
                         boolean fireEvents); @Override HandlerRegistration addValueChangeHandler(ValueChangeHandler<Long> valueChangeHandler); @Override void fireEvent(GwtEvent<?> event); @Override Widget asWidget(); void notifyValueChange(String value); void setEnabled(boolean enabled); void setId(String id); void setPlaceholder(String placeholder); void setMaxLength(int maxLength); boolean isInvalidKeyCode(int key,
                                    boolean isShiftPressed);  }### Answer:
@Test public void testSetId() { String id = "field_id"; integerBox.setId(id); verify(view).setId(eq(id)); }