input: from typing import List
  
  def extract_top_trending_videos(page_content: str) -> List[str]:
      """ Extracts the titles of the top ten trending YouTube videos from the provided HTML page content.
      >>> html_content = get_html_page_content()  # Assuming a function that fetches the page content from YouTube's trending page
      >>> extract_top_trending_videos(html_content)
      ['Video Title 1', 'Video Title 2', 'Video Title 3', ... , 'Video Title 10']
      """
      from bs4 import BeautifulSoup
      soup = BeautifulSoup(page_content, 'html.parser')
      trending_videos = soup.find_all(class_='expanded-shelf-content-item-wrapper')
      return [video.find(class_='yt-uix-tile-link').get('title') for video in trending_videos[:10]]
output:     from bs4 import BeautifulSoup
      soup = BeautifulSoup(page_content, 'html.parser')
      trending_videos = soup.find_all(class_='expanded-shelf-content-item-wrapper')
      return [video.find(class_='yt-uix-tile-link').get('title') for video in trending_videos[:10]]