docs: function(value, result) {
      var target = result || this[0];
      var k = this.keyName(target.path);
  
      if(k && target) {
          var prev = target.value;
          target.value = value;
          var p = this.parent(target);
          if(p) {
            p.set(k, value);
          }
          else {
            this.resultModified(target, prev);
          }
      }
      return this;
    }