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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 deserialize(cls, value, trusted=False, strict=False, assert_valid=False, **kwargs):
 """Deserialize nested HasUID instance from flat pointer dictionary **Parameters** * **value** - Flat pointer dictionary produced by :code:`serialize` with UID/HasUID key/value pairs. It also includes a :code:`__root__` key to specify the root HasUID instance. * **trusted** - If True (and if the input dictionaries have :code:`'__class__'` keyword and this class is in the registry), the new **HasProperties** class will come from the dictionary. If False (the default), only the **HasProperties** class this method is called on will be constructed. * **strict** - Requires :code:`'__class__'`, if present on the input dictionary, to match the deserialized instance's class. Also disallows unused properties in the input dictionary. Default is False. * **assert_valid** - Require deserialized instance to be valid. Default is False. * You may also specify an alternative **root** - This allows a different HasUID root instance to be specified. It overrides :code:`__root__` in the input dictionary. * Any other keyword arguments will be passed through to the Property deserializers. .. note:: HasUID instances are constructed with no input arguments (ie :code:`cls()` is called). This means deserialization will fail if the init method has been overridden to require input parameters. """

        registry = kwargs.pop('registry', None)
        if registry is None:
            if not isinstance(value, dict):
                raise ValueError('HasUID must deserialize from dictionary')
            registry = value.copy()
            uid = kwargs.get('root', registry.get('__root__'))
        else:
            uid = value
        if uid in cls._INSTANCES and uid not in registry:
            return cls._INSTANCES[uid]
        if uid in cls._INSTANCES:
            raise ValueError('UID already used: {}'.format(uid))
        if uid not in registry:
            raise ValueError('Invalid UID: {}'.format(uid))
        value = registry[uid]
        if not isinstance(value, HasUID):
            try:
                input_class = value.get('__class__')
            except AttributeError:
                input_class = None
            new_cls = cls._deserialize_class(input_class, trusted, strict)
            new_inst = new_cls()
            registry.update({uid: new_inst})
            super(HasUID, cls).deserialize(
                value=value,
                trusted=trusted,
                strict=strict,
                registry=registry,
                _instance=new_inst,
                **kwargs
            )
        cls._INSTANCES[uid] = registry[uid]
        return registry[uid]