code: def print_metrics(self) -> None:
      if self.exact_match is not None:
          print(f"Exact Match = {self.exact_match}")
      if self.f1 is not None:
          print(f"F1 = {self.f1}")
      if self.bleu is not None:
          print(f"BLEU = {self.bleu}")
  
file_path: pytext/pytext/metrics/seq2seq_metrics.py
imports: import collections
  from typing import Dict, NamedTuple
  from pytext.metrics import ClassificationMetrics
label_desc: Use image node_id 1 for calling the Seq2SeqMetrics obj's underlying member method code with example usage: obj.print_metrics() without return types