dw.value.EnumValueEach EnumValue has a base value and a display value. The type of the base value can be either String or Integer. Every EnumValue has a display value.
If the value of an Enumeration type object attribute is
null, when that attribute is accessed an EnumValue is returned
that has a base value of null, rather than null
itself. This means that empty(object.attribute) would be
false, and empty(object.attribute.value) would be
true