public boolean add(final S s, final long bulk) {
        allContainedElementsClassChecked = false;
        final Long current = this.map.get(s);
        if (current != null) {
            this.map.put(s, current + bulk);
            return false;
        } else {
            this.map.put(s, bulk);
            return true;
        }
    }
@return true if it is guaranteed that all contained elements/objects are of the same type/class and not null (but not
necessarily, i.e., they can have the same type/class, but we may return false here if it was not analysed/identified)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/BulkSet.java