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