code: def threadsafe_call(self, fn, *args, **kwargs):
          
          def handler():
              try:
                  fn(*args, **kwargs)
              except Exception:
                  warn("error caught while excecuting async callback\n%s\n",
                       format_exc())
  
          def greenlet_wrapper():
              gr = greenlet.greenlet(handler)
              gr.switch()
  
          self._async_session.threadsafe_call(greenlet_wrapper)
docs: Wrapper around `AsyncSession.threadsafe_call`.