code: def doc_to_target(self, doc, turnid=None):
      # Default to prediction of last turn.
      if turnid is None:
          turnid = len(doc["questions"]["input_text"])
      raw_text = doc["answers"]["input_text"][turnid - 1]
      return " " + raw_text
  
imports: import inspect
  import transformers.data.metrics.squad_metrics
  import lm_eval.datasets.coqa.coqa
  from lm_eval.base import Task, rf, mean
  from itertools import zip_longest
label_desc: Use image node_id 13 for calling the CoQA obj's underlying member method code with example usage: obj.doc_to_target(doc, turnid) and returns: unknown