code: @SuppressWarnings("deprecation")
      public Datastore createDatastore(final MongoClient mongoClient, final String dbName) {
          return new DatastoreImpl(this, mongoClient, dbName);
      }
docs: It is best to use a Mongo singleton instance here.
  
  @param mongoClient the representations of the connection to a MongoDB instance
  @param dbName      the name of the database
  @return a Datastore that you can use to interact with MongoDB