public void FileFormatterOk()
        {
            FileFormatters formatters = new FileFormatters();
            string         result     = formatters.Format("key", "value");

            Assert.AreEqual("key_value", result);
        }
        public void FileFormatterKo()
        {
            FileFormatters formatters = new FileFormatters();
            string         result     = formatters.Format("key", null);

            Assert.AreEqual("key", result);
            result = formatters.Format(null, "value");
            Assert.AreEqual("_value", result);
            result = formatters.Format(null, null);
            Assert.AreEqual(string.Empty, result);
        }