code: function(auditRuleName, config) {
          if (!(auditRuleName in this.rules_))
              this.rules_[auditRuleName] = {};
          this.rules_[auditRuleName].config = config;
      }
docs: Sets the user-specified configuration for the given audit rule. This will
  vary in structure from rule to rule; see individual rules for
  configuration options.
  @param {string} auditRuleName
  @param {Object} config