# Copyright (c) 2021 Huawei Technologies Co.,Ltd. All rights reserved.
#
# StratoVirt is licensed under Mulan PSL v2.
# You can use this software according to the terms and conditions of the Mulan
# PSL v2.
# You may obtain a copy of Mulan PSL v2 at:
#         http:#license.coscl.org.cn/MulanPSL2
# THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY
# KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
# NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
# See the Mulan PSL v2 for more details.
"""define common decorator"""


class Singleton():
    """Decorate to a singleton class"""
    def __init__(self):
        self.name = 'singleton'

    def __new__(cls, *args, **kwargs):
        if not hasattr(cls, "_instance"):
            orig = super(Singleton, cls)
            cls._instance = orig.__new__(cls, *args, **kwargs)

        return cls._instance