code: def merge_dict(a, b):
      r"""Merge b into a (2 nested dictionaries)"""
      if isinstance(a, dict):
          if isinstance(b, dict):
              for key in b:
                  if key in a:
                      a[key] = merge_dict(a[key], b[key])
                  else:
                      a[key] = b[key]
      else:
          a = b
  
imports: import argparse
  import copy
  import csv
  import os
  import os.path
  import random
  import numpy
  import yaml
  import graphgym.contrib
  from graphgym.utils.comp_budget import match_baseline_cfg
  from graphgym.utils.io import makedirs_rm_exist, string_to_python
label_desc: Use image node_id 8 for calling a global function with example usage: merge_dict(a, b) without return types