code: def test_concat_transition_main_video_first(self):
      new_src_segments, new_dst_segments = helpers.compute_segments(
          "concat",
          src_duration=30.33,
          dst_duration=64.8,
          src_fps=29.97,
          dst_fps=30.0,
          metadata=None,
          video_paths=["main", "after"],
          src_video_path_index=0,
          transition=af.TransitionConfig(
              effect=af.TransitionEffect.CIRCLECLOSE, duration=4.0
          ),
      )
  
      self.assert_equal_segment_lists(
          new_src_segments, [Segment(start=0.0, end=28.33)]
      )
      self.assert_equal_segment_lists(
          new_dst_segments, [Segment(start=0.0, end=28.33)]
      )
  
imports: import os
  import unittest
  from typing import List
  from unittest.mock import MagicMock, patch
  from augly.utils import Segment
  from augly.utils.base_paths import ASSETS_BASE_DIR
  from augly.video import helpers
  from augly.video.augmenters import ffmpeg
label_desc: Use image node_id 12 for calling the MetadataUnitTest obj's underlying member method code with example usage: obj.test_concat_transition_main_video_first() without return types