input: Write a python function to extract the title from a given URL using the requests library.
  assert extract_title('https://www.nytimes.com/2020/11/19/us/denver-police-protest.html') == 'Police Reclaim Denver Streets From Protesters - The New York Times'
  assert extract_title('https://www.example.com') == 'Example Domain'
output: def extract_title(url):
      import requests
      from bs4 import BeautifulSoup
      
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      return soup.title.string.strip()