input: Write a python function to scrape headlines from given URLs.
  assert scrape_headlines(['http://example.com/page1']) == ['Headline1 from page1', 'Headline2 from page1']
  assert scrape_headlines(['http://example.com/page1', 'http://example.com/page2']) == ['Headline1 from page1', 'Headline2 from page1', 'Headline1 from page2']
  assert scrape_headlines(['http://example.com/page1', 'http://example.com/page2', 'http://example.com/page3']) == ['Headline1 from page1', 'Headline2 from page1', 'Headline1 from page2', 'Headline2 from page2', 'Headline1 from page3']
output: import requests
  from bs4 import BeautifulSoup
  
  def scrape_headlines(urls):
      headlines = []
      for url in urls:
          response = requests.get(url)
          soup = BeautifulSoup(response.content, 'html.parser')
          # Assuming headlines are within <h1> tags for simplicity
          for headline in soup.find_all('h1'):
              headlines.append(headline.get_text())
      return headlines