Performs the desired Conversion.

        :param request: The webob Request object describing the
                        request.
        :param response: The webob Response object describing the
                         response.
        :param data: The data dictionary returned by the prepare()
                     method.

        :returns: A string, the results of which are the desired
                  conversion.

def convert(self, request, response, data):
        """
        Performs the desired Conversion.

        :param request: The webob Request object describing the
                        request.
        :param response: The webob Response object describing the
                         response.
        :param data: The data dictionary returned by the prepare()
                     method.

        :returns: A string, the results of which are the desired
                  conversion.
        """

        client_addr = request.environ.get('REMOTE_ADDR', '-')
        if (self.modifier.param != 'c' and
                'bark.useragent_ip' in request.environ):
            client_addr = request.environ['bark.useragent_ip']

        return client_addr