graph = graph.callForGraph(
    new KeyedGrouping<>(
      Arrays.asList(GroupingKeys.label()),
      Arrays.asList(new Count()),
      Arrays.asList(GroupingKeys.label()),
      Arrays.asList(new Count())
    )
  );

graph = graph.callForGraph(
    new KeyedGrouping<>(
      Arrays.asList(GroupingKeys.label(), GroupingKeys.property("gender")),
      Arrays.asList(new Count(), new AverageProperty("age")),
      Arrays.asList(GroupingKeys.label(), GroupingKeys.property("classYear")),
      Arrays.asList(new Count())
    )
  );

graph = graph.callForGraph(
    new KeyedGrouping<>(
      Arrays.asList(GroupingKeys.label(), new GetYearOfDate<>()),
      Arrays.asList(new Count(), new MinProperty("age"), new MaxProperty("age")),
      Arrays.asList(GroupingKeys.label()),
      Arrays.asList(new Count())
    )
  );

private static class GetYearOfDate<V extends Vertex> implements KeyFunction<V, String> {
  @Override
  public String getKey(V vertex) {
    String dayOfWeek = "unknown";
    if (vertex.hasProperty("birthday")) {
      dayOfWeek = vertex.getPropertyValue("birthday").getDate().getDayOfWeek().name();
    }
    return dayOfWeek;
  }
 ...
}