code: @XmlElementDecl(namespace = "http://www.w3.org/1998/Math/MathML", name = "emptyset")
      public JAXBElement<ConstantType> createEmptyset(ConstantType value) {
          return new JAXBElement<ConstantType>(_Emptyset_QNAME, ConstantType.class, null, value);
      }
docs: Create an instance of {@link JAXBElement }{@code <}{@link ConstantType }{@code >}}