input: Write a function to parse the given URL and print out the protocol, domain name, and path using Python. The function should use the `urllib.parse` module to perform the URL parsing.
  assert url_parser('https://www.example.com/path/to/file')==(('Protocol: https', 'Domain name: www.example.com', 'Path: /path/to/file'))
  assert url_parser('http://test.com/some/path')==('Protocol: http', 'Domain name: test.com', 'Path: /some/path')
  assert url_parser('https://abc123.net')==('Protocol: https', 'Domain name: abc123.net', 'Path: ')
  assert url_parser('')==('Protocol:', 'Domain name:', 'Path:')
output: def url_parser(url):
      from urllib.parse import urlparse
      parsed_url = urlparse(url)
      protocol = f"Protocol: {parsed_url.scheme}"
      domain = f"Domain name: {parsed_url.netloc}"
      path = f"Path: {parsed_url.path}"
      return (protocol, domain, path)