@Override
        public void serialize(final CustomId customId, final JsonGenerator jsonGenerator, final SerializerProvider serializerProvider)
                throws IOException, JsonGenerationException {
            // when types are not embedded, stringify or resort to JSON primitive representations of the
            // type so that non-jvm languages can better interoperate with the TinkerPop stack.
            jsonGenerator.writeString(customId.toString());
        }
A mock identifier for use in ensuring that custom serializers work around element identifiers.

@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/structure/io/util/CustomId.java