input: Write a function to parse the given URL and print out the protocol, domain name, and path. The function should use Python's `urllib.parse` module to achieve this. If the input URL is valid, the function should print the protocol, domain name, and path. If the input URL is empty or invalid, the function should print appropriate error messages.
  assert parse_url('https://www.example.com/path/to/file')==None, "Protocol: https\nDomain name: www.example.com\nPath: /path/to/file"
  assert parse_url('http://test.com/test')==None, "Protocol: http\nDomain name: test.com\nPath: /test"
  assert parse_url('')=="Invalid URL: The input URL is empty."
  assert parse_url(None)=="Invalid URL: The input is None."
  assert parse_url('invalid-url')=="Invalid URL: The input does not seem to be a valid URL."
output: def parse_url(url):
      if url is None:
          print("Invalid URL: The input is None.")
          return
      if url == "":
          print("Invalid URL: The input URL is empty.")
          return
      try:
          parsed_url = urllib.parse.urlparse(url)
          if not parsed_url.scheme or not parsed_url.netloc:
              raise ValueError
          print(f"Protocol: {parsed_url.scheme}")
          print(f"Domain name: {parsed_url.netloc}")
          print(f"Path: {parsed_url.path}")
      except ValueError:
          print("Invalid URL: The input does not seem to be a valid URL.")