Types derived with prost::Oneof can be encoded but not decoded?

My scenario is: I need to store a serialized `prost::Oneof` type. When reading from storage, I want to deserialize this Oneof type and then use it along with other information to construct a protobuf message for further processing. I noticed that types derived with `prost::Oneof` have an encode method but (as far as I find) not a decode method. Did I miss something?