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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""The singleton metaclass for ensuring only one instance of a class."""
import abc
from typing import Any
class Singleton(abc.ABCMeta, type):
"""Singleton metaclass for ensuring only one instance of a class"""
_instances = {}
def __call__(cls, *args: Any, **kwargs: Any) -> Any:
"""Call method for the singleton metaclass"""
if cls not in cls._instances:
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
return cls._instances[cls]
class AbstractSingleton(abc.ABC, metaclass=Singleton):
"""Abstract singleton class for ensuring only one instance of a class"""
pass
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