code: function(config) {
  
  			if (config.rules) {
  				Object.keys(config.rules).forEach(function(ruleId) {
  					var ruleConfig = config.rules[ruleId];
  
  					if (typeof ruleConfig === "string") {
  						config.rules[ruleId] = RULE_SEVERITY[ruleConfig.toLowerCase()] || 0;
  					} else if (Array.isArray(ruleConfig) && typeof ruleConfig[0] === "string") {
  						ruleConfig[0] = RULE_SEVERITY[ruleConfig[0].toLowerCase()] || 0;
  					}
  				});
  			}
  		}
docs: Converts new-style severity settings (off, warn, error) into old-style
  severity settings (0, 1, 2) for all rules. Assumption is that severity
  values have already been validated as correct.
  @param {Object} config The config object to normalize.
  @returns {void}