class_docstr: Inference engine subclass to run inference with `translate.py`.
  
  Args:
      opt: inference options
class_docstr_tok: ["Inference","engine","subclass","to","run","inference","with","`","translate.py","`",".","Args",":","opt",":","inference","options"]
code: def infer_file_parallel(self):
      assert (
          self.opt.world_size > 1
      ), "World size must be greater than 1."
      for device_id in range(self.opt.world_size):
          self.queue_instruct[device_id].put(("infer_file", self.opt))
      scores, preds = [], []
      for device_id in range(self.opt.world_size):
          scores.append(self.queue_result[device_id].get())
          preds.append(self.queue_result[device_id].get())
      return scores[0], preds[0]
  
imports: import json
  from onmt.constants import CorpusTask, DefaultTokens, ModelTask
  from onmt.inputters.dynamic_iterator import build_dynamic_dataset_iter
  from onmt.utils.distributed import ErrorHandler, spawned_infer
  from onmt.utils.logging import init_logger
  from onmt.transforms import get_transforms_cls, make_transforms, TransformPipe
label_desc: Use image node_id 6 for calling the InferenceEnginePY obj's underlying member method code with example usage: obj.infer_file_parallel() and returns: scores,  preds