### Question:
DateTimeSelectorView implements DateTimeSelector.View { @PostConstruct void init() { dateSelectorContainer.appendChild(dateSelector.getElement()); timeSelectorContainer.appendChild(timeSelector.getElement()); dateSelector.setOnInputBlurCallback(this::onBlurCallback); timeSelector.setOnInputBlurCallback(this::onBlurCallback); dateSelector.setPlaceholder(placeholderHelper.getPlaceholderSample(BuiltInType.DATE.toString())); timeSelector.setPlaceholder(placeholderHelper.getPlaceholderSample(BuiltInType.TIME.toString())); } @Inject  DateTimeSelectorView(final HTMLDivElement dateSelectorContainer,
                                final HTMLDivElement timeSelectorContainer,
                                final DateSelector dateSelector,
                                final TimeSelector timeSelector,
                                final ConstraintPlaceholderHelper placeholderHelper); @Override DateTimeValue getValue(); @Override void setValue(final DateTimeValue value); @Override void setOnValueChanged(final Consumer<Event> onValueChanged); @Override void setOnValueInputBlur(final Consumer<BlurEvent> blurEvent); @Override void select(); @Override void init(final DateTimeSelector presenter);  }### Answer:
@Test public void testInit() { final Element dateSelectorElement = mock(Element.class); final Element timeSelectorElement = mock(Element.class); final String datePlaceHolder = "date placeholder"; final String timePlaceHolder = "time placeholder"; when(dateSelector.getElement()).thenReturn(dateSelectorElement); when(timeSelector.getElement()).thenReturn(timeSelectorElement); when(placeholderHelper.getPlaceholderSample(BuiltInType.DATE.toString())).thenReturn(datePlaceHolder); when(placeholderHelper.getPlaceholderSample(BuiltInType.TIME.toString())).thenReturn(timePlaceHolder); view.init(); verify(dateSelectorContainer).appendChild(dateSelectorElement); verify(timeSelectorContainer).appendChild(timeSelectorElement); verify(dateSelector).setPlaceholder(datePlaceHolder); verify(timeSelector).setPlaceholder(timePlaceHolder); }