code: function _fnProccess(node, condition, isAnd) {
                  if (angular.isArray(condition)) {
                      return for_each_filter(node, condition, isAnd);
                  } else {
                      var _key      = condition.field,
                          _callback = condition.callback,
                          _iO, _keysO, _lenO;
  
                      if (_key === '_$') {
                          _keysO = Object.keys(node);
                          _lenO  = _keysO.length;
                          for (_iO = 0; _iO < _lenO; _iO++) {
                              if (_fnCheck(_callback, node[_keysO[_iO]])) {
                                  return true;
                              }
                          }
                      } else if (angular.isDefined(node[_key])) {
                          return _fnCheck(_callback, node[_key]);
                      }
                  }
              }
docs: `fnProcess` to call `_fnCheck`. If `condition` is `array` then call `for_each_filter`
  else will call `_fnCheck`. Specical `condition.field` is `_$` then apply `condition.callback` for all field, if have `field` invaild then `return true`.
  
  @param node
  @param condition
  @param isAnd
  @returns {null|boolean}
  @private