- const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
- const Reflection *bus_reflection = bus_mapping.GetReflection();
- if (!bus_reflection->HasField(bus_mapping, descriptor)) {
- return default_value;
- }
- const MIDIControllerProto &controller_proto =
- static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
- return controller_proto.controller_number();