code: def dedup_list(arr):
      new_arr = []
      for e in arr:
          if e not in new_arr:
              new_arr.append(e)
      return new_arr
  
imports: import os
  import copy
  import json
  import random
  from typing import Optional
  from parlai.utils.misc import warn_once
  from parlai.utils.data import DatatypeHelper
  from parlai.core.opt import Opt
  from parlai.core.teachers import DialogTeacher
  from parlai.core.params import ParlaiParser
  from parlai.core.message import Message
  from parlai.utils.io import PathManager
  from parlai.tasks.wizard_of_internet import constants
  from .mutators import normalize_reply, get_knowledge_appended_context, get_knowledge_sentence_with_special_tokens_only
  from .build import build
  from .constants import FeedbackType, TITLE_PASSAGE_DELIMITER, OK_LABEL, NOT_OK_LABEL
label_desc: Use image node_id 2 for calling a global function with example usage: dedup_list(arr) and returns: new_arr