code: @XmlElementDecl(namespace = "http://www.opengis.net/citygml/relief/1.0", name = "Elevation", substitutionHeadNamespace = "http://www.opengis.net/gml", substitutionHeadName = "_Object")
      public JAXBElement<LengthType> createElevation(LengthType value) {
          return new JAXBElement<LengthType>(_Elevation_QNAME, LengthType.class, null, value);
      }
docs: Create an instance of {@link JAXBElement }{@code <}{@link LengthType }{@code >}
  
  @param value
  Java instance representing xml element's value.
  @return
  the new instance of {@link JAXBElement }{@code <}{@link LengthType }{@code >}