AuthTLS should be used to setup a secure authentication using TLS.

Code returns the error code for err if it was produced by the rpc system.

gRPC Codec to be used to encode/decode requests for a given content type.

ErrorDesc returns the error description of err if it was produced by the rpc system.

Errorf returns an error containing an error code and a description; Errorf returns nil if c is OK.

We use this to wrap any debug handlers so we preserve the signature Debug.{Method}.