code: def extract_favicon(bs4):
      
  
      favicon = []
  
      selectors = [
          'link[rel="icon"]',
          'link[rel="Icon"]',
          'link[rel="ICON"]',
          'link[rel^="shortcut"]',
          'link[rel^="Shortcut"]',
          'link[rel^="SHORTCUT"]'
      ]
  
      for selector in selectors:
  
          icons = bs4.select(selector)
  
          if icons:
  
              for icon in icons:
  
                  if icon.has_attr('href'):
  
                      favicon.append(icon['href'])
  
      return favicon
docs: Extracting favicon url from BeautifulSoup object
  
      :param bs4: `BeautifulSoup`
      :return: `list` List of favicon urls