For logging or debugging, the Log class allows for writing data to a file or Firebug console by way of FirePHP.
Mode
The mode is either off, file, or fb. The value is set in the container, but you can override it manually using the public mode method.
Write
// Log the string 'asdf'
Log::write('asdf');
If the log mode is file, unless a path is specified as the second parameter, the file is created/written at
the logs directory set in the container, with a filename of log-<today’s date>.php.