// code placeholder
_dbSettings1.ClusterConfigurator = builder =>
            {
                builder.Subscribe<ConnectionPoolAddedConnectionEvent>(e =>
               {
                   connectionAdded++;
                   //Console.WriteLine("Total Added Connections: " + connectionAdded);
               });
                builder.Subscribe<ConnectionPoolRemovedConnectionEvent>(e =>
               {
                   connectionRemoved++;
                   //Console.WriteLine("Total Removed Connections: " + connectionRemoved);
               });
            }; 
_mongoClient = new MongoClient(_dbSettings);

// code placeholder
Value cannot be null.
Parameter name: factory
Source: Microsoft.Extensions.Logging.Abstractions
Thread started: <Thread Pool> #21
  at Microsoft.Extensions.Logging.LoggerFactoryExtensions.CreateLogger[T] (Microsoft.Extensions.Logging.ILoggerFactory factory) [0x00003] in <d7a3ca84869f48e0aa5c354ee22cb1ee>:0 
  at MongoDB.Driver.Core.Clusters.ClusterFactory.<ProcessClusterEnvironment>g__LogIfExternalEnvironment|9_2 (System.String host, System.String environment, System.String documentationUrl, System.String[] suffixes) [0x00022] in <9a38b6dbb2264f9885b4250438ce22a4>:0 
  at MongoDB.Driver.Core.Clusters.ClusterFactory.<ProcessClusterEnvironment>g__LogIfCosmosDB|9_0 (System.String host) [0x00000] in <9a38b6dbb2264f9885b4250438ce22a4>:0 
  at MongoDB.Driver.Core.Clusters.ClusterFactory.ProcessClusterEnvironment (MongoDB.Driver.Core.Configuration.ClusterSettings settings) [0x0002b] in <9a38b6dbb2264f9885b4250438ce22a4>:0 
  at MongoDB.Driver.Core.Clusters.ClusterFactory.CreateCluster () [0x00007] in <9a38b6dbb2264f9885b4250438ce22a4>:0 
  at MongoDB.Driver.Core.Configuration.ClusterBuilder.BuildCluster () [0x00006] in <9a38b6dbb2264f9885b4250438ce22a4>:0 
  at MongoDB.Driver.ClusterRegistry.CreateCluster (MongoDB.Driver.ClusterKey clusterKey) [0x000cf] in <6926c8350547439997c522a25b1c60d3>:0 
  at MongoDB.Driver.ClusterRegistry.GetOrCreateCluster (MongoDB.Driver.ClusterKey clusterKey) [0x00021] in <6926c8350547439997c522a25b1c60d3>:0 
  at MongoDB.Driver.MongoClient..ctor (MongoDB.Driver.MongoClientSettings settings) [0x0003e] in <6926c8350547439997c522a25b1c60d3>:0