)
result.add_done_callback(lambda _: self.histogram.add_item(time.time() - start))
result.add_done_callback(lambda _: self.adjust_task_count(-1))
)
result.add_done_callback(lambda _: self.histogram.add_item(time.time() - start))
result.add_done_callback(lambda _: self.adjust_task_count(-1))