Gauge that computes the ratio of two different gauges.
Inheritance: ICounterValue
        public void RateCounterGaugeGetValueAndResetGetsTheValueFromJson()
        {
            RawCounterGauge readIoBytes = new RawCounterGauge("READ IO BYTES", "readIoBytes", AzureWebApEnvironmentVariables.App, new CacheHelperTests());
            RawCounterGauge writeIoBytes = new RawCounterGauge("WRITE IO BYTES", "writeIoBytes", AzureWebApEnvironmentVariables.App, new CacheHelperTests());
            RawCounterGauge otherIoBytes = new RawCounterGauge("OTHER IO BYTES", "otherIoBytes", AzureWebApEnvironmentVariables.App, new CacheHelperTests());

            RatioCounterGauge readIoBytesRate = new RatioCounterGauge(@"\Process(??APP_WIN32_PROC??)\Private Bytes", readIoBytes, writeIoBytes);

            double value1 = readIoBytesRate.GetValueAndReset();
            Assert.IsTrue(value1 != 0);

               SumUpCountersGauge writeAndOtherBytes = new SumUpCountersGauge("Sum Up Bytes", writeIoBytes, otherIoBytes);
               RatioCounterGauge totalReadIoBytesRate = new RatioCounterGauge(@"\Process(??APP_WIN32_PROC??)\Private Bytes", readIoBytes, writeAndOtherBytes);
               double value2 = totalReadIoBytesRate.GetValueAndReset();

            Assert.IsTrue(value2 != 0);
            Assert.IsTrue(value1 >= value2);

               RatioCounterGauge totalReadIoBytesPercentage = new RatioCounterGauge(@"\Process(??APP_WIN32_PROC??)\Private Bytes", readIoBytes, writeAndOtherBytes, 100);
               double percentage = totalReadIoBytesPercentage.GetValueAndReset();
            Assert.IsTrue(percentage != 0);
            Assert.IsTrue(Math.Abs((value2 * 100) - percentage) < 1);
        }
 public void RatioCounterGaugeDoesNotThrowWithNullGauges()
 {
     RatioCounterGauge readIoBytesRate = new RatioCounterGauge(@"\Process(??APP_WIN32_PROC??)\Private Bytes", null, null);
     readIoBytesRate.GetValueAndReset();
 }