public void Throws_If_Adding_Empty_File_Name(string fileName)
        {
            var dirBuilder = new DirectoryBuilder(Path.GetTempPath());

            var exception = Assert.Throws <ArgumentException>(() =>
            {
                dirBuilder.AddFile(fileName);
            });

            Assert.Equal("fileName", exception.ParamName);
            Assert.Contains("File name can't be null or empty", exception.Message);

            exception = Assert.Throws <ArgumentException>(() =>
            {
                dirBuilder.AddFile(fileName);
            });

            Assert.Equal("fileName", exception.ParamName);
            Assert.Contains("File name can't be null or empty", exception.Message);
        }