/// <summary>
        /// Creates a random file (one with a unique name and contents) in the web root of apiCassini
        ///
        /// The file name is created by <code>var fileName     = "randomFile_{0}.{1}".format(6.randomLetters(), extension);</code>
        /// </summary>
        /// <param name="apiCassini"></param>
        /// <param name="extension"></param>
        /// <returns></returns>
        public static string create_Random_File(this API_Cassini apiCassini, string extension)
        {
            var fileName     = "randomFile_{0}.{1}".format(6.randomLetters(), extension);
            var fileContents = "This is a random file created by API_Cassini.create_Random_File extension method".line().add_5_RandomLetters();

            return(apiCassini.create_File(fileName, fileContents));
        }