Facing error while starting map job.

While starting a map job i am getting this error.

TypeError: __init__() got an unexpected keyword argument _user_agent

Here is how i am starting the map function.

control.start_map(name='Export Device Health Logs',
      handler_spec='data_process.process_health_logs',
      reader_spec='mapreduce.input_readers.DatastoreInputReader',
      mapper_parameters={"input_reader":{'entity_kind': 'models.DeviceHealth','email':user.email,'to_date':to_date,'from_date':from_date},'output_writer': {'bucket_name': bucket_name,
                'content_type': 'text/plain'}},
      shard_count=1,
      output_writer_spec='mapreduce.output_writers.GoogleCloudStorageConsistentOutputWriter',
      mapreduce_parameters={'done_callback':'/tasks/mapreduce/done/export_health_data',
                              'done_callback_queue':'mapreduce-done'})