Binboo.Core.Commands.UnknowCommand.ReportCommandNotFound C# (CSharp) Method

        private string ReportCommandNotFound()
        {
            StringBuilder output = new StringBuilder();
            output.AppendFormat("Unknown command: {0}.", _commandName);

            var inputSoundex = _commandName.SoundEx();

            var probableCommand = _commands.Where(candidate => candidate.Id.SoundEx() == inputSoundex).Select(pair => pair.Id).SingleOrDefault();
            if (probableCommand != null)
            {
                output.AppendFormat("\r\nDid you mean \"{0}\" ?", probableCommand);
            }

            return output.ToString();
        }