public void should_return_correct_value_for_very_large_number()
        {
            int    start          = int.MaxValue;
            int    end            = int.MaxValue;
            string expectedString = $"{start} * {end} = 4611686014132420609 " + Environment.NewLine;

            Assert.Equal(expectedString, Mutiplication.MutiplicationTable(start, end));
        }
        public void should_return_empty_string_when_start_bigger_than_end()
        {
            int    start          = 2;
            int    end            = 1;
            string expectedString = "";

            Assert.Equal(expectedString, Mutiplication.MutiplicationTable(start, end));
        }
        public void should_return_one_row_when_start_equals_end()
        {
            int    start          = 1;
            int    end            = 1;
            string expectedString = "1 * 1 = 1 " + Environment.NewLine;

            Assert.Equal(expectedString, Mutiplication.MutiplicationTable(start, end));
        }
        public void should_return_more_rows_when_start_less_than_end()
        {
            int    start          = 2;
            int    end            = 5;
            string expectedString =
                "2 * 2 = 4  " + Environment.NewLine +
                "2 * 3 = 6  3 * 3 = 9  " + Environment.NewLine +
                "2 * 4 = 8  3 * 4 = 12 4 * 4 = 16 " + Environment.NewLine +
                "2 * 5 = 10 3 * 5 = 15 4 * 5 = 20 5 * 5 = 25 " + Environment.NewLine;

            Assert.Equal(expectedString, Mutiplication.MutiplicationTable(start, end));
        }