How to return a variable from a timer function

Hi all,
How can i return something else than Float or None from the timer function ?

import bpy

counter = 0

def run_10_times():
    global counter
    counter += 1
    print(counter)
    if counter == 10:
        return None
    return 0.1

bpy.app.timers.register(run_10_times)

you can’t. timers use the return value to know how frequently to update- just use some kind of proxy global variable or something instead.