code: def registry(self):
      if self._registry is None:
          if self.multiproc:
              self._pid = os.getpid()
          self._registry = self.prometheus_client.REGISTRY
      else:
          if self.multiproc:
              assert self._pid is not None
              assert (
                  os.getpid() == self._pid
              ), "The current process's different than the process which the prometheus client gets created"
  
      return self._registry
  
imports: from __future__ import annotations
  import logging
  import os
  import sys
  import typing
  from functools import partial
  from typing import TYPE_CHECKING
label_desc: Use image node_id 3 for calling the PrometheusClient obj's underlying member method code with example usage: obj.registry() and returns: self