public void IsUserNameValid_ShouldCheckIfNameIsNotNull()
{
string message;
string Name = null;
registrationValidator.IsUserNameValid(Name, out message);
Assert.Matches("cannot be empty", message);
}
private void NicknameText_Leave(object sender, EventArgs e)
{
registrationValidator.IsUserNameValid(nicknameText.Text, out message);
nicknameLabel.Text = message;
}