"""
This module contains python patterns to ease programming and usage.
"""
from __future__ import annotations
from typing import Optional

class Borg:
    """Singleton pattern Borg singleton pattern"""
    _shared_state = {}
    def __init__(self):
        self.__dict__ = self._shared_state

class SingletonMeta(type):
    """
    The Singleton class can be implemented in different ways in Python. Some
    possible methods include: base class, decorator, metaclass. We will use the
    metaclass because it is best suited for this purpose.
    """

    _instance: Optional[Singleton] = None

    def __call__(self) -> Singleton:
        if self._instance is None:
            self._instance = super().__call__()
        return self._instance
"""
This module contains python patterns to ease programming and usage.
"""
from __future__ import annotations
from typing import Optional

class Borg:
    """Singleton pattern Borg singleton pattern"""
    _shared_state = {}
    def __init__(self):
        self.__dict__ = self._shared_state

class SingletonMeta(type):
    """
    The Singleton class can be implemented in different ways in Python. Some
    possible methods include: base class, decorator, metaclass. We will use the
    metaclass because it is best suited for this purpose.
    """

    _instance: Optional[Singleton] = None

    def __call__(self) -> Singleton:
        if self._instance is None:
            self._instance = super().__call__()
        return self._instance
This module contains python patterns to ease programming and usage. Singleton pattern Borg singleton pattern The Singleton class can be implemented in different ways in Python. Some     possible methods include: base class, decorator, metaclass. We will use the     metaclass because it is best suited for this purpose.