input: Write a python function to extract comments and users from a webpage.
  assert extract_comments_users("https://www.example.com") == [("user1", "comment1"), ("user2", "comment2")]
  assert extract_comments_users("https://www.sample.com") == [("alice", "This is a great article!"), ("bob", "I completely agree with this.")]
  assert extract_comments_users("https://www.test.com") == []
output: def extract_comments_users(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
  
      comments_users = []
      comments_section = soup.find_all('div', class_='comment')
      for comment in comments_section:
          user = comment.find('span', class_='user').text.strip()
          comment_text = comment.find('p', class_='text').text.strip()
          comments_users.append((user, comment_text))
  
      return comments_users