private static void addStringItems(HashMap<Integer, Inspector> children, WeightedSetItem out) {
        //{"a":1, "b":2}
        children.get(1).traverse((ObjectTraverser) (key, value) -> {
            if (value.type() == STRING){
                throw new IllegalArgumentException("Expected an integer argument, but got the string '" +
                                                   value.asString() + "'");
            }
            out.addToken(key, (int)value.asLong());
        });
    }
Translates a list of grouping requests on JSON form to a list in the grouping language form
container-search/src/main/java/com/yahoo/search/query/SelectParser.java