@Override
    public String toString() {

        return "Selector{" +
                "selectionList=" + selectionList +
                ", groupByList=" + groupByList +
                ", havingExpression=" + havingExpression +
                ", orderByList=" + orderByList +
                ", limit=" + limit +
                ", offset=" + offset +
                '}';
    }
Selector selecting query output stream attributes
modules/siddhi-query-api/src/main/java/io/siddhi/query/api/execution/query/selection/Selector.java