/// <summary>
    /// Read input and print out river flow.
    /// </summary>
    static void getRiverFlow()
    {
        int section = getSection();

        double[] width    = getItemArray("What is the width of each section?", section);
        double[] depth    = getItemArray("What is the depth of each section?", section);
        double[] velocity = getItemArray("What is the velocity of each section?", section);

        RiverFlow rf        = new RiverFlow(section, width, depth, velocity);
        double    riverFlow = rf.CalculateRiverFlow();

        Console.WriteLine("River Flow is : {0}", riverFlow);
    }
    public void testWithSingleData()
    {
        Console.WriteLine("Single data test:");
        try {
            int      section  = testSingleData.getSection();
            double[] width    = testSingleData.getWidth();
            double[] depth    = testSingleData.getDepth();
            double[] velocity = testSingleData.getVelocity();
            double   expected = testSingleData.getExpected();

            RiverFlow rf        = new RiverFlow(section, width, depth, velocity);
            double    riverFlow = rf.CalculateRiverFlow();

            printTestInfo(section, width, depth, velocity, expected, riverFlow);

            if (riverFlow != expected)
            {
                throw new Exception("Not expected: testWithSingleData");
            }
        } catch (Exception) {
            return;
        }
        Console.WriteLine("Single data test is done...\n");
    }