public static async Task <TestData> CreateFiles(int nbFiles, int sizeKb, string folder)
        {
            foreach (var _ in Enumerable.Range(0, nbFiles))
            {
                await TestFileHelper.NewFile(folder, sizeKb);
            }
            await Task.Delay(150); // for filesystem latency

            return(new TestData
            {
                Directories = new List <DirectoryInfo> {
                    new DirectoryInfo(folder)
                }
            });
        }