code: public <T> List<T> mgetDocuments(String index, Class<T> type, Object... ids)  throws ElasticSearchException{
  		return mgetDocuments(  index, _doc,type, ids);
  	}
docs: For Elasticsearch 7 and 7+
  https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-multi-get.html
  @param index _mget
  test/_mget
  test/type/_mget
  test/type/_mget?stored_fields=field1,field2
  _mget?routing=key1
  @param type
  @param ids
  @param <T>
  @return
  @throws ElasticSearchException