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# -*- Mode: Python; coding: utf-8; indent-tabs-mode: nil; tab-width: 4 -*-
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# Snappy Ecosystem Tests
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# Copyright (C) 2017 Canonical
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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class Singleton(type):
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"""Class that represents a singleton entity.
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Usage: Specify metaclass=Singleton in those classes you want to be
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Example: MyClass(metaclass=Singleton).
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And automatically the same instance will be returned when creating
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def __call__(cls, *args, **kwargs):
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if cls not in cls.__instances:
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cls.__instances[cls] = super(Singleton, cls).__call__(
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return cls.__instances[cls]