protobuf object to bytes

gistfile1.txt

Note note = Note.newBuilder()
                    .setName("But list")
                    .setContent("Buy:\n"
                        + "- Beer\n"
                        + "- Beef\n"
                        + "- Bacon\n"
                        + "- Leg for C++ client part")
                    .setId(((long) (Math.random() * 900000000)))
                    .setType(NoteType.BASIC).build();
        Envelope requesetEnvelope = Envelope.newBuilder().addNote(note).setType(Type.SAVE_NOTE).build();
        byte[] bytesToSend = requesetEnvelope.toByteArray();//we're done here, send in any way you want.