public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
            try {
                if (tree != null) {
                    this.isOuter = isOuter;
                    tree.accept(this);
                    if (checkRaw)
                        checkRaw(tree, env);
                }
            } catch (CompletionFailure ex) {
                completionError(tree.pos(), ex);
            }
        }