# SPDX-FileCopyrightText: Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: LicenseRef-NvidiaProprietary
#
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# property and proprietary rights in and to this material, related
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"""This package defines interfaces of observer pattern."""

from abc import abstractmethod, ABC

class Subject(ABC):
    @abstractmethod
    def attach(self, observer):
        return NotImplemented

    @abstractmethod
    def detach(self, observer):
        return NotImplemented

    @abstractmethod
    def notify(self):
        return NotImplemented

class Observer(ABC):
    @abstractmethod
    def update_data(self, subject) -> None:
        return NotImplemented