code: func Must(u UUID, err error) UUID {
  	if err != nil {
  		panic(err)
  	}
  	return u
  }
docs: // Must is a helper that wraps a call to a function returning (UUID, error)
  // and panics if the error is non-nil. It is intended for use in variable
  // initializations such as
  //	var packageUUID = uuid.Must(uuid.FromString("123e4567-e89b-12d3-a456-426655440000"));