code: public static PTtlAction toProtobuf(TtlAction ttlAction) {
      if (ttlAction == null) {
        return PTtlAction.DELETE;
      }
      switch (ttlAction) {
        case DELETE:
          return PTtlAction.DELETE;
        case FREE:
          return PTtlAction.FREE;
        default:
          throw new IllegalStateException("Unknown ttl action: " + ttlAction);
      }
    }
docs: Converts Wire type to Protobuf type.
  
  @param ttlAction {@link PTtlAction}
  @return {@link TtlAction} equivalent