@Override public Void visitNor(final Stream<Void> negativeDisjoints) { if (norIsForbidden) { final String message = String.format("The filter operation 'not' is not available in API versions >= %d. " + "Please rephrase your search query without using 'not'.", getForbiddenSchemaVersion()); throw InvalidRqlExpressionException.fromMessage(message, dittoHeaders); } else { // force the stream to evaluate criteria on children negativeDisjoints.count(); return null; } }