code: def get_title(self, context_keys=()):
      return (
          "index",
          "question",
          "document",
          "predicted_answers",
          "predicted_ans_starts",
          "predicted_ans_ends",
          "true_answers",
          "true_ans_starts",
          "true_ans_ends",
      )
  
imports: import re
  import string
  from typing import Dict, List, Set, Tuple, Union
  import numpy
  from pytext.common.constants import Stage
  from pytext.metric_reporters.channel import Channel, ConsoleChannel, FileChannel
  from pytext.metric_reporters.metric_reporter import MetricReporter
  from pytext.metrics.squad_metrics import SquadMetrics
  from pytext.utils.data import merge_token_labels_to_slot, parse_slot_string, Slot
  from scipy.optimize import linear_sum_assignment
label_desc: Use image node_id 1 for calling the MultiSpanQAFileChannel obj's underlying member method code with example usage: obj.get_title(context_keys) and returns: str,  str,  str,  str,  str,  str,  str,  str,  str