code: def concat(
      video_paths: List[str],
      output_path: Optional[str] = None,
      src_video_path_index: int = 0,
      transition: Optional[af.TransitionConfig] = None,
      metadata: Optional[List[Dict[str, Any]]] = None,
  ) -> str:
      """
      Concatenates videos together. Resizes all other videos to the size of the
      `source` video (video_paths[src_video_path_index]), and modifies the sample
      aspect ratios to match (ffmpeg will fail to concat if SARs don't match)
  
      @param video_paths: a list of paths to all the videos to be concatenated (in order)
  
      @param output_path: the path in which the resulting video will be stored.
          If not passed in, the original video file will be overwritten
  
      @param src_video_path_index: for metadata purposes, this indicates which video in
          the list `video_paths` should be considered the `source` or original video
  
      @param transition: optional transition configuration to apply between the clips
  
      @param metadata: if set to be a list, metadata about the function execution
          including its name, the source & dest duration, fps, etc. will be appended
          to the inputted list. If set to None, no metadata will be appended or returned
  
      @returns: the path to the augmented video
      """
      func_kwargs = helpers.get_func_kwargs(
          metadata, locals(), video_paths[src_video_path_index]
      )
  
      concat_aug = af.VideoAugmenterByConcat(
          video_paths,
          src_video_path_index,
          transition,
      )
      concat_aug.add_augmenter(
          video_paths[src_video_path_index], output_path
      )
  
      if metadata is not None:
          helpers.get_metadata(
              metadata=metadata,
              function_name="concat",
              video_path=video_paths[src_video_path_index],
              **func_kwargs,
          )
  
      return output_path or video_paths[src_video_path_index]
  
imports: import functools
  import math
  import os
  import shutil
  import tempfile
  from typing import Any, Callable, Dict, List, Optional, Tuple, Union
  import numpy
  from augly import audio, image, utils
  from augly.audio import utils
  from augly.video import helpers, utils
  from augly.video.augmenters import cv2, ffmpeg
label_desc: Use image node_id 11 for calling a global function with example usage: concat(video_paths, output_path, src_video_path_index, transition, metadata) and returns: unknown