Benchmark for ConfigurationRoot get method change using for loop instead of Reverse method call

ConfigurationRootBenchmark

using System.Collections.Generic;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Memory;

namespace Microsoft.Extensions.Primitives.Performance
{
    public class ConfigurationBenchmark
    {
        private IConfigurationRoot configurationRoot;
        private IConfigurationRoot configurationRoot2;

        [GlobalSetup]
        public void Setup()
        {
            // Arrange
            var dic1 = new Dictionary<string, string>()
            {
                {"Mem1:KeyInMem1", "ValueInMem1"}
            };
            var dic2 = new Dictionary<string, string>()
            {
                {"Mem2:KeyInMem2", "ValueInMem2"}
            };

            var memConfigSrc1 = new MemoryConfigurationSource { InitialData = dic1 };
            var memConfigSrc2 = new MemoryConfigurationSource { InitialData = dic2 };

            var provider1 = new MemoryConfigurationProvider(memConfigSrc1);
            var provider2 = new MemoryConfigurationProvider(memConfigSrc2);

            configurationRoot = new ConfigurationRoot(new IConfigurationProvider[] {
                provider1, provider2
            });

            configurationRoot2 = new ConfigurationRootNew(new IConfigurationProvider[] {
                provider1, provider2
            });
        }

        [Benchmark]
        public string UsingReverse()
        {
            return configurationRoot["Mem1:KeyInMem1"];
        }

        [Benchmark]
        public string UsingForLoop()
        {
            return configurationRoot2["Mem1:KeyInMem1"];
        }
    }
}