public JCTree visitWildcard(WildcardTree node, P p) {
        JCWildcard t = (JCWildcard) node;
        TypeBoundKind kind = M.at(t.kind.pos).TypeBoundKind(t.kind.kind);
        JCTree inner = copy(t.inner, p);
        return M.at(t.pos).Wildcard(kind, inner);
    }