@Override
        public IoY read(final Kryo kryo, final Input input, final Class<IoY> ioyClass) {
            throw new UnsupportedOperationException("IoX writes to Map and can't be read back in as IoX");
        }
Converts an {@link IoX} to a {@link HashMap}.
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/structure/io/IoYIoRegistry.java