code: func SomeUUID(u ble.UUID) Field {
  	return func(p *Packet) error {
  		if u.Len() == 2 {
  			return p.append(someUUID16, u)
  		}
  		if u.Len() == 4 {
  			return p.append(someUUID32, u)
  		}
  		return p.append(someUUID128, u)
  	}
  }
docs: // SomeUUID is one of the incomplete service UUID list.