code: func ValidateURIs(uris ...string) Validatable {
  	return func() error {
  		for i := range uris {
  			uri := uris[i]
  			if len(uri) < 7 {
  				return errors.Wrapf(ErrInvalidURI, "%s at index %d", uris[i], i)
  			}
  			schema := uri[:6]
  			if schema != "tcp://" && schema != "udp://" {
  				return errors.Wrapf(ErrInvalidURI, "%s at index %d", uris[i], i)
  			}
  			if _, err := url.Parse(uri[6:]); err != nil {
  				return errors.Wrapf(ErrInvalidURI, "%s at index %d", uris[i], i)
  			}
  		}
  		return nil
  	}
  }
docs: // ValidateURIs validates the given URIs for neighbor addition/removal.