code: def _make_key(args, kwargs, unhashable, kwd_mark=(object(),)):
      """Simplified version of functools."""
      key = args
      if kwargs:
          key += kwd_mark
          for item in kwargs.items():
              if not isinstance(item[1], Hashable):
                  return unhashable
              key += item
      return key
  
file_path: AIF360/aif360/metrics/metric.py
imports: from abc import abstractmethod
  from collections.abc import Hashable
  from functools import wraps
  from aif360.datasets import Dataset
  from aif360.decorating_metaclass import ApplyDecorator
label_desc: Use image node_id 1 for calling a global function with example usage: _make_key(args, kwargs, unhashable, kwd_mark) and returns: key, unhashable