syntax = "proto2"; package test_protobuf; message Person { optional string name = 1; optional int32 id = 2; optional string email = 3; enum PhoneType { MOBILE = 0; HOME = 1; WORK = 2; } message PhoneNumber { optional string number = 1; optional PhoneType type = 2 [default = HOME]; } repeated PhoneNumber phones = 4; } message AddressBook { repeated Person people = 1; }