package availability import ( "errors" ) type Error interface { Error() string } var ErrUnimplemented Error = errors.New("not implemented") var ErrBusy Error = errors.New("device or resource busy") var ErrNoDevice Error = errors.New("no such device") type errorString struct { s string } func NewError(text string) Error { return &errorString{text} } func (e *errorString) Error() string { return e.s }