class_docstr: A dict property value container that supports change notifications on
  mutating operations.
  
  When a Bokeh model has a ``List`` property, the ``PropertyValueLists`` are
  transparently created to wrap those values. These ``PropertyValueList``
  values are subject to normal property validation. If the property type
  ``foo = Dict(Str, Str)`` then attempting to set ``x.foo['bar'] = 10`` will
  raise an error.
  
  Instances of ``PropertyValueDict`` can be eplicitly created by passing
  any object that the standard dict initializer accepts, for example:
  
  .. code-block:: python
  
      >>> PropertyValueDict(dict(a=10, b=20))
      {'a': 10, 'b': 20}
  
      >>> PropertyValueDict(a=10, b=20)
      {'a': 10, 'b': 20}
  
      >>> PropertyValueDict([('a', 10), ['b', 20]])
      {'a': 10, 'b': 20}
  
  The following mutating operations on dicts automatically trigger
  notifications:
  
  .. code-block:: python
  
      del x[y]
      x[i] = y
      x.clear
      x.pop
      x.popitem
      x.setdefault
      x.update
code: def _saved_copy(self):
      return dict(self)
  
imports: from __future__ import annotations
  import logging
  import copy
  from typing import TYPE_CHECKING, Any, Iterable, TypeVar
  import numpy
label_desc: Use image node_id 2 for calling the PropertyValueDict obj's underlying member method code with example usage: obj._saved_copy() and returns: dict