opts.go
func Ignore(ignore ...func(error) bool) Option {
	return func(s *Sentinel) error {
		s.Lock()
		defer s.Unlock()

		if s.started {
			return ErrAlreadyStarted
		}

		s.ignoreErrors = append(s.ignoreErrors, ignore...)
		return nil
	}
}
func Ignore(ignore ...func(error) bool) Option {
	return func(s *Sentinel) error {
		s.Lock()
		defer s.Unlock()

		if s.started {
			return ErrAlreadyStarted
		}

		s.ignoreErrors = append(s.ignoreErrors, ignore...)
		return nil
	}
}
// Ignore is a sentinel option to add ignore error handlers.