docs: def subtract(dict_a, dict_b, strict=False):
      """a stricter form of subtract_by_key(), this version will only remove an
      entry from dict_a if the key is in dict_b *and* the value at that key
      matches"""
      if not strict:
          return subtract_by_key(dict_a, dict_b)
  
      difference_dict = {}
      for key in dict_a:
          if key not in dict_b or dict_b[key] != dict_a[key]:
              difference_dict[key] = dict_a[key]
  
      return difference_dict