code: def batch_context(self, raw_batch, batch):
      return {
          DatasetFieldName.RAW_SEQUENCE: [
              row["source_sequence"] for row in raw_batch
          ],
          BatchContext.INDEX: [
              row[RawExampleFieldName.ROW_INDEX] for row in raw_batch
          ],
      }
  
imports: from typing import Dict, List, Optional
  from pytext.common.constants import BatchContext, DatasetFieldName, RawExampleFieldName, Stage
  from pytext.data.data_structures.annotation import Annotation, INVALID_TREE_STR
  from pytext.data.tensorizers import Tensorizer
  from pytext.metric_reporters.channel import Channel, ConsoleChannel
  from pytext.metric_reporters.compositional_metric_reporter import CompositionalMetricReporter
  from pytext.metric_reporters.metric_reporter import MetricReporter
  from pytext.metric_reporters.seq2seq_metric_reporter import Seq2SeqFileChannel, Seq2SeqMetricReporter
  from pytext.metrics.intent_slot_metrics import compute_all_metrics, FramePredictionPair
label_desc: Use image node_id 10 for calling the Seq2SeqCompositionalMetricReporter obj's underlying member method code with example usage: obj.batch_context(raw_batch, batch) and returns: dict