code: def during(f):
      
      def decorator(g):
          @wraps(g)
          def h(*args, **kargs):
              tf = Thread(target=f, args=args, kwargs=kargs)
              tf.start()
              r = g(*args, **kargs)
              tf.join()
              return r
          return h
      return decorator
docs: Runs f during the decorated function's execution in a separate thread.