def get_installed_pypackages():
    return {p.project_name.lower(): p for p in pkg_resources.working_set}
def encode(self):
        return {
            'af': ip_address(self.gaddr).vapi_af,
            'grp_address': {
                ip_address(self.gaddr).vapi_af_name: self.gaddr
            },
            'src_address': {
                ip_address(self.saddr).vapi_af_name: self.saddr
            },
            'grp_address_length': self.glen,
        }