'Return the list of firewalls.
:return: A list of firewall objects.
:rtype: ``list`` of :class:`GCEFirewall`'

def ex_list_firewalls(self):

    list_firewalls = []
    request = '/global/firewalls'
    response = self.connection.request(request, method='GET').object
    list_firewalls = [self._to_firewall(f) for f in response.get('items', [])]
    return list_firewalls
