public Builder addCustom(final Class clazz, final Serializer serializer) {
            addOrOverrideRegistration(clazz, id -> GryoTypeReg.of(clazz, id, serializer));
            return this;
        }
Register custom class to serialize with a custom serialization class. Note that calling this method for
a class that is already registered will override that registration.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/gryo/GryoMapper.java