class_docstr: Common part for ConditionalKeyBindings and _MergedKeyBindings.
code: def __init__(self) -> None:
      # `KeyBindings` to be synchronized with all the others.
      self._bindings2: KeyBindingsBase = KeyBindings()
      self._last_version: Hashable = ()
  
imports: from __future__ import annotations
  from abc import ABCMeta, abstractmethod, abstractproperty
  from inspect import isawaitable
  from typing import TYPE_CHECKING, Any, Callable, Coroutine, Hashable, Sequence, Tuple, TypeVar, Union, cast
  from prompt_toolkit.cache import SimpleCache
  from prompt_toolkit.filters import FilterOrBool, Never, to_filter
  from prompt_toolkit.keys import KEY_ALIASES, Keys
label_desc: Use image node_id 1 to create a new _Proxy object from inherited base classes: KeyBindingsBase with example: obj = _Proxy()