text: from typing import Optional
  
  from flask import Flask
  from flask_sqlalchemy import SQLAlchemy
  from flask_httpauth import HTTPBasicAuth
  
  # initialization
  app = Flask(__name__)
  app.config['SECRET_KEY'] = 'the quick brown fox jumps over the lazy dog'
  app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///db.sqlite'
  app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
  
  # extensions
  db = SQLAlchemy(app)
  auth = HTTPBasicAuth()
  
  
  class CC:
      _obj: Optional['ControllerCollection'] = None
  
      @staticmethod
      def get() -> 'ControllerCollection':
          if CC._obj is None:
              raise KeyError()
          return CC._obj
  
      @staticmethod
      def set(obj: 'ControllerColction'):
          CC._obj = obj
  