code: def __reduce__(self):
      if self._jbroadcast is None:
          invalidInputError(
              False, "Broadcast can only be serialized in driver"
          )
      self._pickle_registry.add(self)
      return _from_id_and_type, (self._jbroadcast.id(), self.bigdl_type)
  
file_path: BigDL/python/dllib/src/bigdl/dllib/models/utils/model_broadcast.py
imports: import os
  import sys
  import gc
  from tempfile import NamedTemporaryFile
  from pyspark.broadcast import Broadcast
  from pyspark.broadcast import _from_id
  from bigdl.dllib.nn.layer import Model
  from bigdl.dllib.utils.log4Error import *
label_desc: Use image node_id 5 for calling the ModelBroadcast obj's underlying member method code with example usage: obj.__reduce__() and returns: _from_id_and_type,  self,  self