def Query(self, filter_string="", limit=1000, age=NEWEST_TIME):
    direct_child_urns = []
    for entry in data_store.DB.ResolvePrefix(self.urn, "index:dir/",
                                             limit=limit, token=self.token):
      _, filename = entry[0].split("/", 1)
      direct_child_urns.append(self.urn.Add(filename))

    children = self.OpenChildren(children=direct_child_urns,
                                 limit=limit, age=age)

    if filter_string:
      # Parse the query string.
      ast = AFF4QueryParser(filter_string).Parse()
      filter_obj = ast.Compile(AFF4Filter)

      children = filter_obj.Filter(children)

    return children
:returns:
dataset/ETHPy150Open google/grr/grr/lib/aff4.py/AFF4Volume.Query--crossover with--dataset/ETHPy150Open tabo/django-treebeard/treebeard/models.py/Node.get_next_sibling