public void StrengthByOnlyLetters_StringWithNotOnlyLetters_StrengthReturned() //strength = 0
{
Assert.AreEqual(0, PasswordStrengthLib.StrengthByOnlyLetters("132ab"));
}
public void StrengthByOnlyLetters_StringWithOnlyLetters_StrengthReturned() //strength = -len
{
Assert.AreEqual(-1, PasswordStrengthLib.StrengthByOnlyLetters("a"));
Assert.AreEqual(-4, PasswordStrengthLib.StrengthByOnlyLetters("Aaaa"));
}