[gobwas]

Thats true that such approach also exists.

But it doesn't work well in Go by several reasons.

For example, you usually define interface not in the package where its implemented, but where its needed. Thus you must provide such wrappers in every place where some (subset) of the `Client`'s methods are used.

Another reason is that such thing rejects an ability to use your struct as is, without interfaces (and thus sometimes without heap allocation for your struct).

And, finally, if you want to adopt such approach in proprietary/internal software, where interfaces usually change more often than in libraries, you will change code in N places instead of 1 (in best case); where N is number of instrumentation methods you want to provide "as feature".