public void LongerTest()
        {
            const string input = "9-5+2+7-9";
            const string expectedOutput = "95-2+7+9-";

            var tranlator = new PostfixTranslator();

            string output = tranlator.Tranlate(input);

            Assert.AreEqual(expectedOutput, output);
        }
        public void FirstExampleTest()
        {
            const string input = "9-5+2";
            const string expectedOutput = "95-2+";

            var tranlator = new PostfixTranslator();

            string output = tranlator.Tranlate(input);

            Assert.AreEqual(expectedOutput, output);
        }