reflection: accept interface instead of grpc.Server struct in Register() (#4340)
reflection: accept interface instead of grpc.Server struct in Register() (#4340)


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