private void AddUserOnClick(object sender, EventArgs eventArgs)
        {
            var username = FindViewById <EditText>(Resource.Id.edit_text_username);
            var password = FindViewById <EditText>(Resource.Id.edit_text_password);

            var fileHelper = new FileHelper();
            var dbFilePath = fileHelper.GetLocalFilePath(Resources.GetString(Resource.String.user_db_file));

            var userDataValidationService = new UserDataValidationService();
            var isPasswordValid           = userDataValidationService.ValidatePassword(password.Text);

            if (!isPasswordValid)
            {
                password.RequestFocus();
                password.SetError(Resources.GetString(Resource.String.invalid_password_text), null);
            }
            else
            {
                var userDataAccessService = new UserDataAccessService(dbFilePath);
                var addSuccessful         = userDataAccessService.AddUser(new UserInfo(username.Text, password.Text));
                if (addSuccessful > 0)
                {
                    ShowToast(Resources.GetString(Resource.String.user_add_success));
                    Finish();
                }
                else
                {
                    ShowToast(Resources.GetString(Resource.String.oops_error_text));
                }
            }
        }
        public void TestValidatePassword(string password, bool expected)
        {
            var validationService = new UserDataValidationService();
            var result            = validationService.ValidatePassword(password);

            Assert.Equal(expected, result);
        }