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