anchor.diff:  
   [source,java]
   ----
  -public interface MetaModelService2 {
  +public interface MetaModelService4 {
       Class<?> fromObjectType(String objectType);   // <1>
       String toObjectType(Class<?> domainType);     // <2>
       void rebuild(Class<?> domainType);            // <3>
       List<DomainMember> export();                  // <4>
   
  +    // introduced in MetaModelService2
       enum Sort {                                   // <5>
           VIEW_MODEL, JDO_ENTITY, DOMAIN_SERVICE,
           MIXIN, VALUE, COLLECTION, UNKNOWN;
  
positive.code:     }
      Sort sortOf(Class<?> domainType);             // <6>
      Sort sortOf(Bookmark bookmark);
      Sort sortOf(Class<?> domainType, Mode mode);
      Sort sortOf(Bookmark bookmark, Mode mode);
  }
  ----
  <1> reverse lookup of a domain class' object type
  
negative.code: [[_rgsvc_metadata-api_MetamodelService]]
  = `MetaModelService`
  :Notice: Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at. http://www.apache.org/licenses/LICENSE-2.0 . Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR  CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
  :_basedir: ../../
  :_imagesdir: images/
  
  
  
  The `MetaModelService` service (and its various subtypes) provides access to a number of aspects of Apache Isis' internal metamodel.
  
  
  
  == API
  