class_docstr: Holds per-thread state on mixed precision policies.
class_docstr_tok: ["Holds","per-thread","state","on","mixed","precision","policies","."]
code: def get_policy(self, cls: type[hk.Module]) -> Optional[jmp.Policy]:
      key = key_for_module(cls)
      return self._cls_policy.get(key)
  
imports: import collections
  import contextlib
  import threading
  from typing import TypeVar, Optional, Union
  from haiku._src import base
  from haiku._src import data_structures
  from haiku._src import module
  import jmp
label_desc: Use image node_id 7 for calling the _ThreadState obj's underlying member method code with example usage: obj.get_policy(cls) and returns: self