code: public function getForeignChildren()
      {
          $children = [];
          foreach ($this->dataSource->foreignChildKeys as $keySet) {
              $model = $keySet['foreignModel'];
              unset($keySet['foreignModel']);
              if (!empty($this->foreignObject->{$keySet['foreignId']})) {
                  $keySet['foreignId'] = $this->foreignObject->{$keySet['foreignId']};
                  if (!isset($children[$model])) {
                      $children[$model] = [];
                  }
                  $children[$model][] = $keySet;
              }
          }
  
          return $children;
      }
docs: Get foreign children.
  
  @return [[@doctodo return_type:getForeignChildren]] [[@doctodo return_description:getForeignChildren]]