Resolve a reference to an index to the document containing the index,
        using the index's C{localname} as the content of the link.

def resolve_ref(cls, domain, env, fromdocname, builder, typ, target, node,
                    contnode):
        """
        Resolve a reference to an index to the document containing the index,
        using the index's C{localname} as the content of the link.
        """
        # indexes appear to be automatically generated at doc DOMAIN-NAME
        todocname = "bb-%s" % target

        node = nodes.reference('', '', internal=True)
        node['refuri'] = builder.get_relative_uri(fromdocname, todocname)
        node['reftitle'] = cls.localname
        node.append(nodes.emphasis(cls.localname, cls.localname))
        return node