Stream<String> get emailValue => _email.stream.transform(validateEmail);
  Stream<String> get passwordValue => _password.stream.transform(validatePassword);
  Stream<String> get confirmPass => _confirmPass.stream
          .transform(validateConfirmPassword)
          .doOnData((String c) {
        if (0 != _password.value.compareTo(c))
          _confirmPass.addError('As senhas não são iguais.');
      });
  Stream<String> get nameValue => _name.stream.transform(validateName);
  Stream<bool> get passIcon => _passIcon.stream;
  Stream<bool> get confirmPassIcon => _confirmPassIcon.stream;
  Stream<bool> get register => Observable.combineLatest4(nameValue, emailValue, passwordValue, confirmPass,
      (name, email, password, confirmPass) =>
      (0 == password.compareTo(confirmPass)));