### Question:
DataTypeConstraintEnumeration implements DataTypeConstraintComponent { @Override public String getValue() { refreshEnumerationItemsOrder(); return getEnumerationItems() .stream() .map(DataTypeConstraintEnumerationItem::getValue) .filter(itemValue -> !isEmpty(itemValue)) .collect(joining(SEPARATOR)); } @Inject  DataTypeConstraintEnumeration(final View view,
                                         final DMNClientServicesProxy clientServicesProxy,
                                         final ScrollHelper scrollHelper,
                                         final Event<DataTypeConstraintParserWarningEvent> parserWarningEvent,
                                         final ManagedInstance<DataTypeConstraintEnumerationItem> enumerationItemInstances); @Override String getValue(); @Override void setValue(final String value); @Override void setConstraintValueType(final String type); void refreshView(); void refreshView(final Command onCompleteCallback); @Override Element getElement(); void render(); void scrollToPosition(final int position); List<DataTypeConstraintEnumerationItem> getEnumerationItems();  }### Answer:
@Test public void testGetValue() { final DataTypeConstraintEnumerationItem item1 = mock(DataTypeConstraintEnumerationItem.class); final DataTypeConstraintEnumerationItem item2 = mock(DataTypeConstraintEnumerationItem.class); final DataTypeConstraintEnumerationItem item3 = mock(DataTypeConstraintEnumerationItem.class); when(item1.getValue()).thenReturn("123"); when(item2.getValue()).thenReturn("456"); when(item3.getValue()).thenReturn(""); doReturn(asList(item1, item2)).when(constraintEnumeration).getEnumerationItems(); final String actualValue = constraintEnumeration.getValue(); final String expectedValue = "123, 456"; assertEquals(expectedValue, actualValue); }