class_docstr: Base class for any filter to activate/deactivate a feature, depending on a
  condition.
  
  The return value of ``__call__`` will tell if the feature should be active.
class_docstr_tok: ["Base","class","for","any","filter","to","activate\/deactivate","a","feature",",","depending","on","a","condition",".","The","return","value","of","``","__call__","``","will","tell","if","the","feature","should","be","active","."]
code: def __init__(self) -> None:
      self._and_cache: dict[Filter, Filter] = {}
      self._or_cache: dict[Filter, Filter] = {}
      self._invert_result: Filter | None = None
  
imports: from __future__ import annotations
  from abc import ABCMeta, abstractmethod
  from typing import Callable, Iterable, Union
label_desc: Use image node_id 1 to create a new Filter object  with example: obj = Filter()