public void DeleteAllFilesTest()
        {
            using var tfm = new TempFileManager();
            var result = tfm.CreateFiles(10);

            tfm.DeleteAllFiles();

            Assert.IsTrue(tfm.FilesList().Count() == 0);

            foreach (var fileName in result)
            {
                Assert.IsTrue(File.Exists(fileName) == false);
            }
        }