code: function (config) {
      config = config || {};
      Appender.call(this, config);
  
      /**
       * Log file name, initialized from the configuration. Folders up to the
       * file must exist beforehand.
       */
      this.fileName = config.fileName;
  
      /**
       * Append log events to the end of the file when true, clear the file
       * before writing the first log event otherwise.
       */
      this.appendToFile = (typeof config.append !== 'undefined') ?
        !!config.append :
        true;
  
      /**
       * True to log strings instead of objects
       */
      this.appendStrings = (typeof config.appendStrings !== 'undefined') ?
        config.appendStrings :
        true;
  
      /**
       * The file stream, initialized by the "start" function
       */
      this.stream = null;
    }
docs: Appends a log event to a file.
  
  @constructor
  @extends {Appender}