input: Write a python function to fetch the top ten viewed videos on YouTube using the YouTube API and return a formatted report.
  assert isinstance(get_top_ten_videos(), str)
  assert "Top 10 most viewed YouTube videos this week:" in get_top_ten_videos()
output: def get_top_ten_videos():
      import googleapiclient.discovery
  
      # Set up the YouTube API client
      api_service_name = "youtube"
      api_version = "v3"
      api_key = "YOUR_API_KEY"  # Replace with your YouTube Data API v3 key
  
      youtube = googleapiclient.discovery.build(api_service_name, api_version, developerKey=api_key)
  
      # Request for the top 10 most viewed videos this week
      request = youtube.videos().list(
          part="snippet,statistics",
          chart="mostPopular",
          regionCode="US",  # you can change the region code as needed
          maxResults=10
      )
      response = request.execute()
  
      # Format the report
      report = "Top 10 most viewed YouTube videos this week:\n"
      for i, item in enumerate(response['items'], start=1):
          title = item['snippet']['title']
          views = item['statistics']['viewCount']
          report += f"{i}. {title} - {views} views\n"
  
      return report