https://github.com/dotnet/roslyn/blob/main/docs/features/interceptors.md https://github.com/dotnet/roslyn/blob/main/docs/features/int... Without interceptors,

https://github.com/dotnet/roslyn/blob/main/docs/features/interceptors.md https://github.com/dotnet/roslyn/blob/main/docs/features/int... Without interceptors, source generators can only add new code, but cannot modify any existing code. Interceptors enable method call substitutions.