The from fix start cut rule.
Inheritance: CutRule
        public void DiffTest()
        {
            string source = "reegwvwvw";
            var rule = new CutRuleWithFixedStart(source.Length, 3);
            List<string> cuts = DiffCutter.Cut(source, rule);

            Assert.AreEqual("ree", cuts[0]);
            Assert.AreEqual("reegwv", cuts[1]);
            Assert.AreEqual("reegwvwvw", cuts[2]);
        }
        public void CutRuleTest()
        {
            int length = 12;
            int step = 3;
            var rule = new CutRuleWithFixedStart(length, step);
            CutRuleIterator iterator = rule.GetIterator();

            for (int i = step; i <= length; i += step)
            {
                iterator.Next();
                Assert.AreEqual(0, iterator.GetStartPosition());
                Assert.AreEqual(i, iterator.GetEndPosition());
            }
        }