code: def flush_values(self):
      self._register_atexit()
      for (category, key), value in self._to_flush.items():
          _internal_kv_put(
              _make_key(self.prefix, category, key),
              value,
              overwrite=True,
          )
          self._registered.add((category, key))
      self._to_flush.clear()
  
imports: import atexit
  import logging
  from functools import partial
  from types import FunctionType
  from typing import Callable, Optional, Type, Union
  import ray
  import ray.cloudpickle
  from ray.experimental.internal_kv import _internal_kv_get, _internal_kv_initialized, _internal_kv_put, _internal_kv_del
  from ray.tune.error import TuneError
  from ray.util.annotations import DeveloperAPI
label_desc: Use image node_id 9 for calling the _Registry obj's underlying member method code with example usage: obj.flush_values() without return types