code: def into_buffer(self, buf, offset):
      
      self.payload = containerize(exclude_fields(self))
      self.parser = MsgEphemerisGPSDepF._parser
      self.stream_payload.reset(buf, offset)
      return self.pack_into(buf, offset, self._build_payload)
docs: Produce a framed/packed SBP message into the provided buffer and offset.