':param name_id: The identifier by which the subject is know
among all the participents of the VO
:param issuer: Who am I the poses the query
:param vo_members: The entity IDs of the IdP who I\'m going to ask
for extra attributes
:return: A dictionary with all the collected information about the
subject'

def extend(self, name_id, issuer, vo_members):

    result = []
    for member in vo_members:
        for ass in self.metadata.attribute_consuming_service(member):
            for attr_serv in ass.attribute_service:
                logger.info(('Send    attribute    request    to    %s' % attr_serv.location))
                if (attr_serv.binding != BINDING_SOAP):
                    continue
                session_info = self.saml2client.attribute_query(name_id, attr_serv.location, issuer_id=issuer)
                if session_info:
                    result.append(session_info)
    return result
