Options which can be set when calling
A literal IP address or host name that can be resolved to an IP address.
0.0.0.0 While listening
0.0.0.0 works on all platforms,
the browsers on Windows don't work with the address
You should show the message like
server running on localhost:8080 instead of
server running on 0.0.0.0:8080 if your program supports Windows.
The handler to invoke when route handlers throw an error.