Uses the given username and password for authentication at the given network location and realm.
This method sets the parameters for either the WWW-Authenticate or Proxy-Authenticate
headers in a request. The
get_basic_credentials method is called by
request to retrieve the username and passwords, if they exist. The arguments are:
The network location (usually a URL string) to which the username and password apply.
The name of the server-defined range of URLs that this data applies to.
The username for authentication.
The password for authentication. By default, the password will be transmitted with MIME base-64 encoding.