code: def on_update(self, callback, mode=None):
      return self._subscribe(
          "on_update", "view_method", callback, mode=mode
      )
  
imports: import asyncio
  from random import random
  from functools import partial
  from .dispatch import async_queue, subscribe, unsubscribe
label_desc: Use image node_id 14 for calling the PerspectiveViewProxy obj's underlying member method code with example usage: obj.on_update(callback, mode) and returns: self