input: Write a python function to check if a URL is accessible using the requests module.
  assert check_url("https://www.google.com") == True
  assert check_url("https://www.nonexistentwebsite1234.com") == False
  assert check_url("https://www.github.com") == True
output: def check_url(url):
      import requests
      try:
          response = requests.get(url)
          return response.status_code == 200
      except requests.exceptions.RequestException:
          return False