### Question:
DateSelector implements TypedValueSelector { @Override public void setPlaceholder(final String placeholder) { view.setPlaceholder(placeholder); } @Inject  DateSelector(final DateSelector.View view,
                        final DateValueFormatter dateValueFormatter); @Override String getValue(); @Override void setValue(final String value); @Override void setPlaceholder(final String placeholder); @Override Element getElement(); @Override void setOnInputChangeCallback(final Consumer<Event> onValueChanged); @Override void setOnInputBlurCallback(final Consumer<BlurEvent> blurEvent); @Override void select(); @Override String toDisplay(final String rawValue); boolean isChild(final Object element);  }### Answer:
@Test public void testSetPlaceholder() { final String placeholder = "placeholder"; dateSelector.setPlaceholder(placeholder); verify(view).setPlaceholder(placeholder); }