code: def start_call(self):
      self._continue = True
      self.client.loop.add_callback(self._collect)
      self.call_data_futures = _WeakKeyDictionary()
  
imports: from __future__ import print_function, division, absolute_import
  import asyncio
  import concurrent.futures
  import contextlib
  import time
  from uuid import uuid4
  import weakref
  from .parallel import parallel_config
  from .parallel import AutoBatchingMixin, ParallelBackendBase
label_desc: Use image node_id 5 for calling the DaskDistributedBackend obj's underlying member method code with example usage: obj.start_call() without return types