'List the available network offerings
:rtype ``list`` of :class:`CloudStackNetworkOffering`'

def ex_list_network_offerings(self):

    res = self._sync_request(command='listNetworkOfferings', method='GET')
    netoffers = res.get('networkoffering', [])
    networkofferings = []
    for netoffer in netoffers:
        networkofferings.append(CloudStackNetworkOffering(netoffer['name'], netoffer['displaytext'], netoffer['guestiptype'], netoffer['id'], netoffer['serviceofferingid'], netoffer['forvpc'], self))
    return networkofferings
