New returns a new Transformer.

WithExtraCodes defines extra grpc status codes that are considered retriable.

WithProtoToErrs pass functions that look at protocol buffer message responses to determine if the message actually indicates an error.

Transformer provides an ErrTransformer method that can be used to detect non-retriable errors.

Option is an option for the New() constructor.

ProtoToErr inspects a protocol buffer message and determines if the call was really an error.