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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def preferences_class_prepared(sender, *args, **kwargs):
 """ Adds various preferences members to preferences.preferences, thus enabling easy access from code. """

    cls = sender
    if issubclass(cls, Preferences):
        # Add singleton manager to subclasses.
        cls.add_to_class('singleton', SingletonManager())
        # Add property for preferences object to preferences.preferences.
        setattr(preferences.Preferences, cls._meta.object_name, property(lambda x: cls.singleton.get()))