private HashMap<Integer, Inspector> childMap(Inspector inspector) {
        HashMap<Integer, Inspector> children = new HashMap<>();
        if (inspector.type() == ARRAY){
            inspector.traverse((ArrayTraverser) children::put);

        } else if (inspector.type() == OBJECT){
            if (inspector.field("children").valid()){
                inspector.field("children").traverse((ArrayTraverser) children::put);
            }
        }
        return children;
    }
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