input: Write a function to scrape an online news website and retrieve the headlines using BeautifulSoup. The function should take the URL of the news website as input and print all the headlines found on the page.
  assert scrape_headlines("https://www.example-news.com/")
  assert scrape_headlines("https://www.another-news.com/")
  assert scrape_headlines("https://www.test-news.com/")
output: 
  def scrape_headlines(url):
      import requests
      from bs4 import BeautifulSoup
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
      headlines = soup.find_all('h1') + soup.find_all('h2') + soup.find_all('h3')
      for headline in headlines:
          print(headline.text.strip())
  