'Retrieve account resource limits.
:rtype: ``dict``'

def ex_get_limits(self):

    attributes = ['max-instances', 'max-elastic-ips', 'vpc-max-elastic-ips']
    params = {}
    params['Action'] = 'DescribeAccountAttributes'
    for (index, attribute) in enumerate(attributes):
        params[('AttributeName.%s' % index)] = attribute
    response = self.connection.request(self.path, params=params)
    data = response.object
    elems = data.findall(fixxpath(xpath='accountAttributeSet/item', namespace=NAMESPACE))
    result = {'resource': {}}
    for elem in elems:
        name = findtext(element=elem, xpath='attributeName', namespace=NAMESPACE)
        value = findtext(element=elem, xpath='attributeValueSet/item/attributeValue', namespace=NAMESPACE)
        result['resource'][name] = int(value)
    return result
