package errhttp type ServiceUnavailable interface { ServerError ServiceUnavailable() } type internalServiceUnavailable struct { err error } func ServiceUnavailableWrap(err error) error { return internalServiceUnavailable{ err:err, } } func (receiver internalServiceUnavailable) Error() string { return receiver.err.Error() } func (receiver internalServiceUnavailable) Err() error { return receiver.err } func (internalServiceUnavailable) ServerError() { // Nothing here. } func (internalServiceUnavailable) ServiceUnavailable() { // Nothing here. } func (receiver internalServiceUnavailable) Unwrap() error { return receiver.err }