code: def get_default_arg_values(fn):
      """Gets the arguments and respective default values of a function.
  
      Only arguments with default values are included in the output dictionary.
  
      Args:
          fn (callable): The function to inspect.
  
      Returns:
          dict: A dictionary that maps argument names (str) to their default
          values. The dictionary is empty if no arguments have default values.
      """
      argspec = _inspect_getargspec(fn)
      if argspec.defaults is None:
          return {}
      num_defaults = len(argspec.defaults)
      return dict(zip(argspec.args[-num_defaults:], argspec.defaults))
  
imports: from typing import List, Union
  import inspect
  import funcsigs
  from pydoc import locate
  import copy
  import collections
  import numpy
  import tensorflow
  from texar.tf.hyperparams import HParams
  from texar.tf.utils.dtypes import is_str, is_callable, compat_as_text, _maybe_list_to_array
label_desc: Use image node_id 4 for calling a global function with example usage: get_default_arg_values(fn) and returns: dict, dict