code: def test_ReplaceWithBackground(self):
      self.evaluate_class(
          vidaugs.ReplaceWithBackground(
              source_offset=0.1,
              background_offset=0,
              source_percentage=0.7,
          ),
          fname="replace_with_background",
          metadata_exclude_keys=["dst_duration", "dst_fps"],
      )
  
imports: import json
  import random
  import unittest
  from augly import audio, video
  from augly.tests.base_configs import VideoAugConfig
  from augly.tests.video_tests.base_unit_test import BaseVideoUnitTest
  from augly.utils import VIDEO_METADATA_PATH
  from augly.utils.ffmpeg import get_conditional_for_skipping_video_tests
label_desc: Use image node_id 12 for calling the TransformsVideoUnitTest obj's underlying member method code with example usage: obj.test_ReplaceWithBackground() without return types