input: Write a function to implement a web scraper in Python that extracts the top ten trending YouTube videos. The function should use the `requests` and `BeautifulSoup` libraries to make a request to the YouTube trending page and parse the page content to retrieve the titles of the top ten trending videos. The function should return a list of these video titles. If the page content does not contain the expected elements, the function should return an empty list.
  assert extract_trending_videos() == ["Video Title 1", "Video Title 2", "Video Title 3", "Video Title 4", "Video Title 5", "Video Title 6", "Video Title 7", "Video Title 8", "Video Title 9", "Video Title 10"]
  assert extract_trending_videos() == []  # In case the page structure changes or the request fails
output: def extract_trending_videos():
      import requests
      from bs4 import BeautifulSoup
      url = "https://www.youtube.com/feed/trending"
      headers = {'User-Agent': 'Mozilla/5.0'}
      response = requests.get(url, headers=headers)
      if response.status_code != 200:
          return []
      soup = BeautifulSoup(response.content, 'html.parser')
      video_titles = []
      for title in soup.find_all('a', {'class': 'yt-simple-endpoint style-scope ytd-video-renderer'})[:10]:
          video_titles.append(title.get_text(strip=True))
      return video_titles