docs: def get_children_for(self, parent_alias=None, only_with_aliases=False):
          """Returns a list with with categories under the given parent.
  
          :param str|None parent_alias: Parent category alias or None for categories under root
          :param bool only_with_aliases: Flag to return only children with aliases
          :return: a list of category objects
          """
          self._cache_init()
          child_ids = self.get_child_ids(parent_alias)
          if only_with_aliases:
              children = []
              for cid in child_ids:
                  category = self.get_category_by_id(cid)
                  if category.alias:
                      children.append(category)
              return children
          return [self.get_category_by_id(cid) for cid in child_ids]