input: Write a python function to extract email addresses from a list of URLs.
  assert extract_emails(["http://example.com", "http://example.org"]) == []
  assert extract_emails(["http://test.com"]) == ["contact@test.com"]
  assert extract_emails(["http://sample.org"]) == ["info@sample.org", "support@sample.org"]
output: import re
  import requests
  from bs4 import BeautifulSoup
  
  def extract_emails(urls):
      emails = []
      email_pattern = re.compile(r'[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}')
  
      for url in urls:
          try:
              response = requests.get(url)
              soup = BeautifulSoup(response.text, 'html.parser')
              text = soup.get_text()
              found_emails = email_pattern.findall(text)
              emails.extend(found_emails)
          except Exception as e:
              continue
  
      return list(set(emails))