public synchronized static void initialize(final Configuration configuration) {
        if (!INITIALIZED) {
            INITIALIZED = true;
            GRYO_POOL = GryoPool.build().
                    poolSize(configuration.getInt(GryoPool.CONFIG_IO_GRYO_POOL_SIZE, 256)).
                    version(GryoVersion.valueOf(configuration.getString(GryoPool.CONFIG_IO_GRYO_VERSION, GryoPool.CONFIG_IO_GRYO_POOL_VERSION_DEFAULT.name()))).
                    ioRegistries(configuration.getList(IoRegistry.IO_REGISTRY, Collections.emptyList())).
                    initializeMapper(m -> m.registrationRequired(false)).
                    create();
        }
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
hadoop-gremlin/src/main/java/org/apache/tinkerpop/gremlin/hadoop/structure/io/HadoopPools.java