docstr: Get a list of partition_refs, each partition_ref is a list of shard_refs or a partition_ref
docstr_tok: ["Get","a","list","of","partition_refs",",","each","partition_ref","is","a","list","of","shard_refs","or","a","partition_ref"]
code: def get_partition_refs(
      self,
  ) -> List[Union["ObjectRef", List["ObjectRef"]]]:
      """
      Get a list of partition_refs, each partition_ref is a list of shard_refs or a partition_ref
      """
      # part_shard_refs is a list of partitions, each partition is a dictionary,
      # with key of partition index and value of (list of shard_refs or part_ref)
      part_shard_refs = ray.get(
          [
              local_store.get_partitions_refs.remote()
              for local_store in self.partition_stores.values()
          ]
      )
      result = {}
      for part in part_shard_refs:
          result.update(part)
      return [result[idx] for idx in range(self.num_partitions())]
  
imports: from __future__ import annotations
  from collections import defaultdict
  import ray
  import ray._private.services
  import uuid
  import random
  from bigdl.orca.data import XShards
  from bigdl.orca.ray import OrcaRayContext
  import logging
  from bigdl.dllib.utils.log4Error import invalidInputError
  from numpy import ndarray
  from typing import TYPE_CHECKING, Any, Callable, DefaultDict, Dict, List, Tuple, Union, no_type_check
label_desc: Use image node_id 5 for calling the RayXShards obj's underlying member method code with example usage: obj.get_partition_refs() and returns: unknown