docstr: Registers the value with the global registry.
  
  Raises:
      PicklingError if unable to pickle to provided file.
docstr_tok: ["Registers","the","value","with","the","global","registry",".","Raises",":","PicklingError","if","unable","to","pickle","to","provided","file","."]
code: def register(self, category, key, value):
      """Registers the value with the global registry.
  
      Raises:
          PicklingError if unable to pickle to provided file.
      """
      if category not in KNOWN_CATEGORIES:
          from ray.tune import TuneError
  
          raise TuneError(
              "Unknown category {} not among {}".format(
                  category, KNOWN_CATEGORIES
              )
          )
      self._to_flush[(category, key)] = pickle.dumps_debug(value)
      if _internal_kv_initialized():
          self.flush_values()
  
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 4 for calling the _Registry obj's underlying member method code with example usage: obj.register(category, key, value) without return types