Currently grpc_retry supports retry condition by setting code.Codes.
But it is good if retry condition is defined by error message, status details, etc...
So I propose below options.
// When returns true, it is retriable.
type RetriableFunc func(err error) bool
// WithRetriable sets which error should be retried.
// When this option is set, WithCodes is ignored.
func WithRetriable(ErrorFunc) CallOption
Currently grpc_retry supports retry condition by setting
code.Codes. But it is good if retry condition is defined by error message, status details, etc...So I propose below options.