code: def create_app(*, debug=False, threads=1, bigchaindb_factory=None):
      
  
      if not bigchaindb_factory:
          bigchaindb_factory = BigchainDB
  
      app = Flask(__name__)
      app.wsgi_app = StripContentTypeMiddleware(app.wsgi_app)
  
      CORS(app)
  
      app.debug = debug
  
      app.config['bigchain_pool'] = utils.pool(bigchaindb_factory, size=threads)
  
      add_routes(app)
  
      return app
docs: Return an instance of the Flask application.
  
      Args:
          debug (bool): a flag to activate the debug mode for the app
              (default: False).
          threads (int): number of threads to use
      Return:
          an instance of the Flask application.