'List data centers available with the current subscription.
:return: list of node location objects
:rtype: ``list`` of :class:`.NodeLocation`'

def list_locations(self):

    action = ('/subscriptions/%s/providers/Microsoft.Compute' % self.subscription_id)
    r = self.connection.request(action, params={'api-version': '2015-01-01'})
    for rt in r.object['resourceTypes']:
        if (rt['resourceType'] == 'virtualMachines'):
            return [self._to_location(l) for l in rt['locations']]
    return []
