code: def _new_task(self):
      task = SubWriterTask(
          self.storage,
          self.indexname,
          self.jobqueue,
          self.resultqueue,
          self.subargs,
          self.multisegment,
      )
      self.tasks.append(task)
      task.start()
      return task
  
imports: from __future__ import with_statement
  from multiprocessing import Process, Queue, cpu_count
  from whoosh.compat import queue, xrange, pickle
  from whoosh.codec import base
  from whoosh.writing import SegmentWriter
  from whoosh.externalsort import imerge
  from whoosh.util import random_name
label_desc: Use image node_id 2 for calling the MpWriter obj's underlying member method code with example usage: obj._new_task() and returns: task