def is_authenticated(self):
if self._proxy is None:<EOL><INDENT>return False<EOL><DEDENT>elif self._proxy.has_authentication():<EOL><INDENT>return self._proxy.get_authentication().is_valid()<EOL><DEDENT>else:<EOL><INDENT>return False<EOL><DEDENT>
Tests if an agent is authenticated to this session.

        return: (boolean) - true if valid authentication credentials
                exist, false otherwise
        compliance: mandatory - This method must be implemented.