code: def eval_step(self, batch):
      # for each row in batch, convert tensor to back to text strings
      return Output([self.dict.vec2txt(row) for row in batch.text_vec])
  
imports: from parlai.core.torch_agent import TorchAgent, Output
label_desc: Use image node_id 2 for calling the ParrotAgent obj's underlying member method code with example usage: obj.eval_step(batch) and returns: Output