public void MakeRandomText_LessOrEquilToMaxLangth_Test()
        {
            int expected = 6;

            for (int i = 0; i < 500; i++)
            {
                CaptchaHelper.MaxTextLength = expected;
                string actual = CaptchaHelper.MakeRandomText();
                Assert.IsTrue(actual.Length <= expected);
            }
        }
        public void MakeRandomText_MoreOrEquilToMinLangth_Test()
        {
            int expected = 5;

            for (int i = 0; i < 500; i++)
            {
                CaptchaHelper.MinTextLength = expected;
                var actual = CaptchaHelper.MakeRandomText();
                Assert.IsTrue(actual.Length >= expected);
            }
        }