class_docstr: Encapsulates the actions and resources of a single connection to
  Perspective.
code: def _clear_callbacks(self):
      # remove all callbacks from the view's cache
      for cb in self.manager._callback_cache:
          if cb["client_id"] == self.client_id:
              view = self.manager._get_view(cb["name"])
              if view:
                  view.remove_update(cb["callback"])
      # remove all callbacks from the manager's cache
      self.manager._callback_cache.remove_callbacks(
          lambda cb: cb["client_id"] == self.client_id
      )
  
imports: from random import random
label_desc: Use image node_id 4 for calling the PerspectiveSession obj's underlying member method code with example usage: obj._clear_callbacks() without return types