@Test
public void testApply() {

	SetPropertyFunction<Boolean> setPropertyFunction =
		new SetMultipleFunction();
	DefaultDDMExpressionObserver defaultDDMExpressionObserver =
		new DefaultDDMExpressionObserver();
	DefaultDDMExpressionObserver spy = spy(defaultDDMExpressionObserver);
	setPropertyFunction.setDDMExpressionObserver(spy);
	Boolean result = setPropertyFunction.apply("field", true);
	ArgumentCaptor<UpdateFieldPropertyRequest> argumentCaptor =
		ArgumentCaptor.forClass(UpdateFieldPropertyRequest.class);
	Mockito.verify(
		spy, Mockito.times(1)
	).updateFieldProperty(
		argumentCaptor.capture()
	);
	Assert.assertTrue(result);
	UpdateFieldPropertyRequest updateFieldPropertyRequest =
		argumentCaptor.getValue();
	Map<String, Object> properties =
		updateFieldPropertyRequest.getProperties();
	Assert.assertEquals("field", updateFieldPropertyRequest.getField());
	Assert.assertTrue(properties.containsKey("multiple"));
	Assert.assertTrue((boolean)properties.get("multiple"));
}