MultiFollowQueueNode (@Nullable MultiFollowQueueNode previous, @NotNull PyReferenceExpression referenceExpression) { final PyExpression qualifier = referenceExpression.getQualifier(); final List<PyExpression> previousQualifiers = previous == null ? Collections.emptyList() : previous.myQualifiers; final List<PyExpression> newQualifiers = qualifier == null ? previousQualifiers : ContainerUtil.append(previousQualifiers, qualifier); return new MultiFollowQueueNode(referenceExpression, newQualifiers); }