input: from typing import List
  
  
  def extract_urls(urls: List[str]) -> List[str]:
      """ Create a web scraper that extracts specific data from a given list of websites.
      This function will utilize the Python package BeautifulSoup to parse webpages and 
      extract URLs present in the 'href' attribute of 'a' tags. It will return a list 
      of all extracted URLs.
      Example:
      >>> extract_urls(["http://example.com"])
      ['http://example.com/page1', 'http://example.com/page2']
      """
output:     from bs4 import BeautifulSoup
      import requests
  
      extracted_urls = []
      for url in urls:
          try:
              response = requests.get(url)
              response.raise_for_status()
              soup = BeautifulSoup(response.text, 'html.parser')
              for link in soup.find_all('a', href=True):
                  extracted_urls.append(link['href'])
          except requests.RequestException:
              continue
      
      return extracted_urls