input: Write a python function to fetch and print all the articles, headlines, and hyperlinks from a given URL using BeautifulSoup.
  assert fetch_content('http://example.com') is None
output: def fetch_content(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
  
      articles = soup.find_all('article')
      for article in articles:
          headline = article.find('h1') or article.find('h2') or article.find('h3')
          link = article.find('a', href=True)
          if headline and link:
              print(f'Headline: {headline.get_text()}')
              print(f'Link: {link["href"]}')