MongoDB Service with method Insert

MongoDBService.cs

using System.Threading.Tasks;
using MongoDB.Bson;
using MongoDB.Bson.Serialization;
using MongoDB.Bson.Serialization.Serializers;
using MongoDB.Driver;

namespace VS.Services
{
    public class MongoDBService
    {
        private readonly string _connectionString;

        public MongoDBService(string connectionString)
        {
            this._connectionString = connectionString;
        }

        public async Task Save<T>(T entity)
        {
            await this.Insert(entity, this._connectionString);
            await Task.CompletedTask;
        }

        private async Task Insert<T>(T entity, string connectionString)
        {
            var database = this.GetMongoDatabase(connectionString);
            var collection = database.GetCollection<T>(typeof(T).Name);
            await collection.InsertOneAsync(entity);
            await Task.CompletedTask;
        }

        private IMongoDatabase GetMongoDatabase(string connectionString)
        {
            var mongoUrl = MongoUrl.Create(connectionString);
            var settings = MongoClientSettings.FromUrl(mongoUrl);
            var client = new MongoClient(settings);
            return client.GetDatabase(mongoUrl.DatabaseName);
        }
    }
}