Had a bug: for structs, replaying internal fields did not include initial values of fields.  This caused list of struct serializations emit test to fail.  Note that the solution here (and most of replay in general) may have a bug.  If set a field in a map/list to a struct that was serialized from opposite side, could get into trouble because not preserving initialization of serialized and translated rpc struct.  May need to do deep logging of rpc translated struct for replay.