public boolean test(final Object selection) {
        if (inDoubleSelectPeriod && ((selection == null && lastSelection == null)
                || (selection != null && selection.equals(lastSelection)))) {
            clear();

            DoubleSelectEvent.fire(this);
            return true;

        } else {
            lastSelection = selection;
            inDoubleSelectPeriod = true;
            doubleSelectTimer.cancel();
            doubleSelectTimer.schedule(DOUBLE_SELECT_DELAY);
            return false;
        }
    }
Test that the same object was clicked twice.
stroom-core-client-widget/src/main/java/stroom/widget/util/client/DoubleSelectTester.java