code: def _path(task, opt):
      # Build the data if it doesn't exist.
      build(opt)
      suffix = ""
      dt = opt["datatype"].split(":")[0]
      if dt == "train":
          suffix = "train"
      elif dt == "test":
          suffix = "test"
      elif dt == "valid":
          suffix = "dev"
  
      datafile = os.path.join(
          opt["datapath"],
          "MovieDialog",
          "movie_dialog_dataset",
          "{t}{s}.txt".format(t=tasks[int(task)], s=suffix),
      )
      if int(task) == 4:
          if dt == "train":
              candpath = None
          else:
              candpath = datafile.replace(
                  suffix + ".txt", "cand-{dt}.txt".format(dt=dt)
              )
      else:
          candpath = os.path.join(
              opt["datapath"],
              "MovieDialog",
              "movie_dialog_dataset",
              "entities.txt",
          )
      return datafile, candpath
  
file_path: ParlAI/parlai/tasks/moviedialog/agents.py
imports: from parlai.core.teachers import FbDeprecatedDialogTeacher, MultiTaskTeacher
  from .build import build
  import copy
  import os
label_desc: Use image node_id 1 for calling a global function with example usage: _path(task, opt) and returns: datafile,  candpath