input: Write a python function to extract data from a web page using python requests.
  assert extract_data('https://example.com').startswith('<!doctype html>')  # Example URL, check the beginning of the HTML content
  assert 'Example Domain' in extract_data('https://example.com')  # Check a known string in the content
output: def extract_data(url):
      import requests
      response = requests.get(url)
      return response.text