code: def is_bidirectional(self) -> bool:
      return self.bidirectional
  
imports: import torch
  import numpy
  import pytest
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.modules.seq2seq_encoders import ComposeEncoder, FeedForwardEncoder, Seq2SeqEncoder
  from allennlp.modules import FeedForward
label_desc: Use image node_id 5 for calling the MockSeq2SeqEncoder obj's underlying member method code with example usage: obj.is_bidirectional() and returns: self