code: public static <N> NestedDocument<N> NestedDocument(final N type,
                                                       final URI identity,
                                                       final NamedProperties<N> properties) {
      return NestedDocument(NamespaceBindings(), type, identity, properties);
    }
docs: Factory for {@link NestedDocument}.
  
  <p>
  This builds a new NestedDocument using the supplied data.
  </p>
  
  @param type        the type of the document
  @param identity    the identity of the document
  @param properties  the property list of the document
  @param <N>         the property name type
  @return  a new TopLevelDocument instance