input: Write a function to parse a given URL and print out the protocol, domain name, and path using Python. The function should use the urllib.parse module to achieve this. If the input URL is empty, the function should print "No URL provided".
  
  assert parse_url('https://www.example.com/path/to/file')==['Protocol: https\nDomain name: www.example.com\nPath: /path/to/file']
  assert parse_url('http://www.another-example.com/folder')==['Protocol: http\nDomain name: www.another-example.com\nPath: /folder']
  assert parse_url('')==['No URL provided']
output: def parse_url(url):
      if not url:
          return ["No URL provided"]
      parsed_url = urllib.parse.urlparse(url)
      protocol = f"Protocol: {parsed_url.scheme}"
      domain_name = f"Domain name: {parsed_url.netloc}"
      path = f"Path: {parsed_url.path}"
      return [f"{protocol}\n{domain_name}\n{path}"]