code: def _get_instance_data(self) -> Iterator[Instance]:
      if self._input_file == "-":
          raise ConfigurationError(
              "stdin is not an option when using a DatasetReader."
          )
      elif self._dataset_reader is None:
          raise ConfigurationError(
              "To generate instances directly, pass a DatasetReader."
          )
      else:
          if isinstance(self._dataset_reader, MultiTaskDatasetReader):
              assert (
                  self._multitask_head is not None
              )  # This is properly checked by the constructor.
              yield from self._dataset_reader.read(
                  self._input_file, force_task=self._multitask_head
              )
          else:
              yield from self._dataset_reader.read(self._input_file)
  
imports: from typing import List, Iterator, Optional
  import argparse
  import sys
  import json
  from allennlp.commands.subcommand import Subcommand
  from allennlp.common import logging
  from allennlp.common.checks import check_for_gpu, ConfigurationError
  from allennlp.common.file_utils import cached_path, open_compressed
  from allennlp.common.util import lazy_groups_of
  from allennlp.data.dataset_readers import MultiTaskDatasetReader
  from allennlp.models.archival import load_archive
  from allennlp.predictors.predictor import Predictor, JsonDict
  from allennlp.data import Instance
label_desc: Use image node_id 6 for calling the _PredictManager obj's underlying member method code with example usage: obj._get_instance_data() without return types