code: def test_n_frames(duration, fps, expected_n_frames):
      clip = VideoClip(duration=duration).with_fps(fps)
      assert clip.n_frames == expected_n_frames
  
imports: import copy
  import os
  import numpy
  from PIL import Image
  import pytest
  from moviepy.audio.AudioClip import AudioClip
  from moviepy.audio.io.AudioFileClip import AudioFileClip
  from moviepy.tools import convert_to_seconds
  from moviepy.video.compositing.CompositeVideoClip import CompositeVideoClip
  from moviepy.video.fx.mask_color import mask_color
  from moviepy.video.fx.multiply_speed import multiply_speed
  from moviepy.video.io.VideoFileClip import VideoFileClip
  from moviepy.video.VideoClip import BitmapClip, ColorClip, ImageClip, VideoClip
label_desc: Use image node_id 2 for calling a global function with example usage: test_n_frames(duration, fps, expected_n_frames) without return types