'Determines whether a service uses a global endpoint.
In theory a service can be \'global\' in one partition but regional in
another. In practice, each service is all global or all regional.'

def _is_global_service(self, service_name, partition_name='aws'):

    endpoint_prefix = self._endpoint_prefix(service_name)
    partition = self._get_partition_data(partition_name)
    service = partition['services'].get(endpoint_prefix, {})
    return ('partitionEndpoint' in service)
