*  @param dc       The documentation comment for the interface, or null.
     */
    JCClassDecl interfaceDeclaration(JCModifiers mods, String dc) {
        int pos = S.pos();
        accept(INTERFACE);
        Name name = ident();

        List<JCTypeParameter> typarams = typeParametersOpt();

        List<JCExpression> extending = List.nil();
        if (S.token() == EXTENDS) {
            S.nextToken();
            extending = typeList();
        }
        List<JCTree> defs = classOrInterfaceBody(name, true);
        JCClassDecl result = toP(F.at(pos).ClassDef(
            mods, name, typarams, null, extending, defs));
        attach(result, dc);
        return result;
    }