input: Write a function to parse the given URL and print out the protocol, domain name, and path using Python. The function should take one string parameter representing the URL and use the `urllib.parse.urlparse` function to extract the required components from the URL.
  def parse_url(url):
      import urllib.parse
      
      parsed_url = urllib.parse.urlparse(url)
      
      # Get the protocol
      protocol = parsed_url.scheme
      
      # Get the domain name
      domain_name = parsed_url.netloc
      
      # Get the path
      path = parsed_url.path
      
      # Print the results
      print('Protocol:', protocol)
      print('Domain name:', domain_name)
      print('Path:', path)
      
  assert parse_url('https://www.example.com/path/to/file')==None
  assert parse_url('http://another-example.org/some/page')==None
  assert parse_url('ftp://files.server.net/directory')==None
  assert parse_url('https://sub.domain.com/resource')==None
  assert parse_url('https://www.example.com')==None
output: def parse_url(url):
      import urllib.parse
      
      parsed_url = urllib.parse.urlparse(url)
      
      # Get the protocol
      protocol = parsed_url.scheme
      
      # Get the domain name
      domain_name = parsed_url.netloc
      
      # Get the path
      path = parsed_url.path
      
      # Print the results
      print('Protocol:', protocol)
      print('Domain name:', domain_name)
      print('Path:', path)