input: Write a python function to scrape headlines from a given URL using BeautifulSoup.
  assert scrape_headlines('http://example.com/news') == ['Headline 1', 'Headline 2', 'Headline 3']
  assert scrape_headlines('http://example.com/sports') == ['Sports Headline 1', 'Sports Headline 2']
  assert scrape_headlines('http://example.com/technology') == ['Tech Headline 1', 'Tech Headline 2', 'Tech Headline 3']
output: def scrape_headlines(url):
      import requests
      from bs4 import BeautifulSoup
      
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      
      headlines = []
      for headline in soup.find_all('h2'):  # Assuming headlines are in <h2> tags
          headlines.append(headline.get_text(strip=True))
      
      return headlines