code: function (config) {
      config = config || {};
  
      // Calling base constructor
      LifeCycle.call(this);
  
      /**
       * Appender config
       */
      this.name = config.name;
  
      /**
       * Underlying layout
       */
      this.layout = config.layout;
  
      /**
       * Appender filter
       */
      this.filter = config.filter;
  
      /**
       * Trace level
       */
      this.level = config.level || 'all';
  
      /**
       * Function used to determine whether a level is below the
       * trace level of the Appender
       */
      this.isBelow = config.isLogLevelBelow || function () {
        return true;
      };
    }
docs: Definition of the Appender class
  
  @constructor