input: Write a python function to extract all href links from a given URL.
  assert extract_links('https://example.com') == ['/page1', '/page2', '/page3']
  assert extract_links('https://anotherexample.com') == ['/home', '/about', '/contact']
output: def extract_links(url):
      import requests
      from bs4 import BeautifulSoup
      
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      
      links = []
      for a in soup.find_all('a', href=True):
          links.append(a['href'])
      
      return links