input: 
  from typing import List
  
  def extract_youtube_titles(url: str) -> List[str]:
      """Extract titles of all YouTube videos from a given URL.
      >>> extract_youtube_titles("https://www.youtube.com/user/Thexvid/videos")
      ['Title 1', 'Title 2', 'Title 3']
      >>> extract_youtube_titles("https://www.youtube.com/channel/UC3erB8wlixZSBlHy4pvHQ7w/videos")
      ['Title A', 'Title B', 'Title C']
      """
      import requests
      import re
  
      r = requests.get(url)
      titles = re.findall('<a href="/watch\\?v=([^"]+)">(.+?)</a>', r.content.decode('utf-8'))
      
      return [title[1] for title in titles]
  
  # Example usage:
  # print(extract_youtube_titles("https://www.youtube.com/user/Thexvid/videos"))
  
output:     import requests
      import re
  
      r = requests.get(url)
      titles = re.findall('<a href="/watch\\?v=([^"]+)">(.+?)</a>', r.content.decode('utf-8'))
      
      return [title[1] for title in titles]