input: from typing import List
  
  def extract_links(urls: List[str]) -> List[str]:
      """ Extracts URLs from a list of webpages using BeautifulSoup.
      >>> extract_links(["<url_of_webpage>"])
      ['<url1>', '<url2>', '<url3>']
      >>> extract_links(["<url_of_another_webpage>"])
      []
      """
      extracted_urls = []
      for url in urls:
          webpage = requests.get(url)
          soup = BeautifulSoup(webpage.content, 'html.parser')
          links = soup.find_all('a')
          for link in links:
              extracted_urls.append(link.get('href'))
      return extracted_urls
output:     extracted_urls = []
      for url in urls:
          try:
              webpage = requests.get(url)
              webpage.raise_for_status()
              soup = BeautifulSoup(webpage.content, 'html.parser')
              links = soup.find_all('a')
              for link in links:
                  href = link.get('href')
                  if href and href.startswith('http'):
                      extracted_urls.append(href)
          except requests.exceptions.RequestException:
              continue
      return extracted_urls