def groups(self, group=None):
        if group is None:
            path = "api/groups/"
            return list(map(Group.from_dict, self._get(path)))
        else:
            path = "api/groups/{0}".format(group)
            return Group.from_dict(self._get(path))
Retrieve a list of all groups, or the specified group.  If group is 
dataset/ETHPy150Open adafruit/io-client-python/Adafruit_IO/client.py/Client.groups