Impossible for graph implementations to provide a class resolver for Gryo IO

As far as I can tell there is no way for a graph implementation to specify a classresolver for the following code:

g.io(IoCore.gryo()).writer().create()

The problem is that inside the graph implementation we need to be able to do this:

public <I extends Io> I io(final Io.Builder<I> builder) {
  Io io = builder.graph(this).registry(MyRegistry.INSTANCE).classResolver(MyClassReolver.INSTANCE).create();

but only supplying a registry is supported.
Other solutions could be to design GryoIo for extension so that it can be wrapped or to change the signature of Graph#io to:

public default Io io(final Io.Builder<I> builder)

I would probably go for the signature change, so the graph is responsible for deciding the implementation that is returned.