code: function getIn(record, accessor, ctx) {
      var v = record;
      var keys = getPathKeys(accessor, ctx);
      if (utils_1.isFn(record.getIn)) {
          return record.getIn(keys);
      }
      var len = keys.length;
      for (var i = 0; i < len; i++) {
          var key = keys[i];
          v = utils_1.isObj(v)
              ? utils_1.isFn(v.get)
                  ? v.get(key)
                  : v[key]
              : undefined;
      }
      return v;
  }
docs: get a deep child
  
  @param record The object to update, it can be a plain object or a class instance
  @param accessor A lambda function to get the key path, support dot, [''], [""], [1], **do not** support dynamic variable, function call, e.g.
  @param ctx Dynamic key map.