public void TestConnection()
        {
            // Arrange
            var unitOfWork = new UnitOfWork();

            // Act
            unitOfWork.Context<SampleContext>().Users.Any();

            // Assert
            unitOfWork.Dispose();
        }
        public void FillDatabase()
        {
            // Arrange
            var unitOfWork = new UnitOfWork();
            var context = unitOfWork.Context<SampleContext>();
            if (context.Files.Any())
            {
                throw new InvalidOperationException("Seems that thre are some data in database.");
            }
        
            (new DatabaseFill()).Fill(context);

            // Assert
            unitOfWork.Save();
        }