code: def prometheus_client(self):
      if self.multiproc and not self._imported:
          # step 1: check environment
          assert (
              "prometheus_client" not in sys.modules
          ), "prometheus_client is already imported, multiprocessing will not work properly"
  
          assert (
              self.multiproc_dir
          ), f"Invalid prometheus multiproc directory: {self.multiproc_dir}"
          assert os.path.isdir(self.multiproc_dir)
  
          os.environ["PROMETHEUS_MULTIPROC_DIR"] = self.multiproc_dir
  
      # step 2:
      import prometheus_client
      import prometheus_client.exposition
      import prometheus_client.metrics
      import prometheus_client.metrics_core
      import prometheus_client.multiprocess
      import prometheus_client.parser
  
      self._imported = True
      return prometheus_client
  
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 2 for calling the PrometheusClient obj's underlying member method code with example usage: obj.prometheus_client() and returns: prometheus_client