private static boolean containsFalse(CompositeItem composite) {
        for (ListIterator<Item> i = composite.getItemIterator(); i.hasNext(); )
            if (i.next() instanceof FalseItem) return true;
        return false;
    }
Handle FALSE items in the immediate children of this

@return true if this composite was replaced by FALSE
container-search/src/main/java/com/yahoo/prelude/query/QueryCanonicalizer.java