cleanup: remove ac.events (unused) and related dead code (#2385)
cleanup: remove ac.events (unused) and related dead code (#2385)


menghanl/grpc-go,dfawley/grpc-go,menghanl/grpc-go,thinkerou/grpc-go,grpc/grpc-go,dfawley/grpc-go,grpc/grpc-go,stanley-cheung/grpc-go,stanley-cheung/grpc-go,thinkerou/grpc-go