input: 
  def scrape_links(url: str) -> list:
      """ This function scrapes a webpage and collects all the links from it.
      It returns a list of strings where each string is a valid URL found on the webpage.
      
      >>> scrape_links("http://www.example.com/")
      ['http://www.iana.org/domains/example']
      """
      import requests as req
      from bs4 import BeautifulSoup
      
      r = req.get(url)
      soup = BeautifulSoup(r.text, 'html.parser')
      links = soup.find_all('a')
      return [link.get('href') for link in links if link.get('href')]
  
output:     import requests as req
      from bs4 import BeautifulSoup
      
      r = req.get(url)
      soup = BeautifulSoup(r.text, 'html.parser')
      links = soup.find_all('a')
      return [link.get('href') for link in links if link.get('href')]