code: def return_testvideo_path(fmt="av"):
      """
      returns Test video path
      """
      supported_fmts = {
          "av": "BigBuckBunny_4sec.mp4",
          "vo": "BigBuckBunny_4sec_VO.mp4",
          "ao": "BigBuckBunny_4sec_AO.mp4",
      }
      req_fmt = fmt if (fmt in supported_fmts) else "av"
      path = "{}/Downloads/Test_videos/{}".format(
          tempfile.gettempdir(), supported_fmts[req_fmt]
      )
      return os.path.abspath(path)
  
imports: import os
  import cv2
  import numpy
  import pytest
  import shutil
  import logging
  import platform
  import requests
  import tempfile
  from os.path import expanduser
  from mpegdash.parser import MPEGDASHParser
  from vidgear.gears.helper import reducer, dict2Args, mkdir_safe, delete_ext_safe, check_output, extract_time, create_blank_frame, is_valid_url, logger_handler, delete_file_safe, validate_audio, validate_video, validate_ffmpeg, get_video_bitrate, get_valid_ffmpeg_path, download_ffmpeg_binaries, check_gstreamer_support, generate_auth_certificates, get_supported_resolution, dimensions_to_resolutions, retrieve_best_interpolation
  from vidgear.gears.asyncio.helper import generate_webdata, validate_webdata
label_desc: Use image node_id 2 for calling a global function with example usage: return_testvideo_path(fmt) and returns: os