What is the correct way to include well known types?

[idc77]

generated code has e.g.

import '../../../google/protobuf/timestamp.pb.dart' as $2;
import '../../../google/protobuf/wrappers.pb.dart' as $3;

but those libraries aren't present.

What is the correct way to include those libraries?

[davidpanic]

This is still an issue two years later, any plans to fix this?