/*
 * 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.
 */
package org.apache.tinkerpop.gremlin.structure.io;

/**
 * Represents a low-level serialization class that can be used to map classes to serializers.  These implementation
 * create instances of serializers from other libraries (e.g. creating a {@code Kryo} instance).
 *
 * @author Stephen Mallette (http://stephen.genoprime.com)
 */
public interface Mapper<T> {
    /**
     * Create a new instance of the internal object mapper that an implementation represents.
     */
    public T createMapper();

    public interface Builder<B extends Builder> {
        public B addRegistry(final IoRegistry registry);
    }
}

@@ -851,16 +851,70 @@
 re.io;%0A%0A
+import org.apache.tinkerpop.gremlin.structure.Graph;%0A%0A
 /**%0A * R
@@ -1365,53 +1365,504 @@
     
-public interface Builder%3CB extends Builder%3E %7B
+/**%0A     * Largely a marker interface for builders that construct %7B@link Mapper%7D instances.%0A     */%0A    public interface Builder%3CB extends Builder%3E %7B%0A%0A        /**%0A         * Adds a vendor supplied %7B@link IoRegistry%7D to the %7B@code Mapper.Builder%7D which enables it to check for%0A         * vendor custom serializers to add to the %7B@link Mapper%7D.  All %7B@link Io%7D implementations should expose%0A         * this method via this %7B@link Builder%7D so that it is compatible with %7B@link Graph#io%7D.%0A         */
 %0A   

Add more javadoc around refactored Io.