text: var ReplaceRuleModel = BaseRuleModel.extend({
    defaults: function() {
      return _.extend(BaseRuleModel.prototype.defaults(), {
        ruleType: RQ.RULE_TYPES.REPLACE,
        pairs: [
          this.getDefaultPair()
        ]
      });
    },
  
    getDefaultPair: function() {
      return { from: '', to: '', status: RQ.RULE_STATUS.INACTIVE };
    },
  
    getPairs: function() {
      return this.get('pairs');
    },
  
    setPair: function(index, pair) {
      var pairs = this.getPairs();
      pairs[index] = pair;
    }
  });