class_docstr: An immutable wrapper around dictionaries that implements the complete :py:class:`collections.abc.Mapping`
  interface. It can be used as a drop-in replacement for dictionaries where immutability and ordering are desired.
code: def __contains__(self, key):
      return key in self._dict
  
file_path: pytensor/pytensor/misc/frozendict.py
imports: import collections
  import functools
  import operator
  from collections.abc import Mapping
label_desc: Use image node_id 3 for calling the frozendict obj's underlying member method code with example usage: obj.__contains__(key) and returns: unknown