private static String optLongToStr(final OptionalLong optLong) {
        return optLong.isPresent()
                ? ModelStringUtil.formatCsv(optLong.getAsLong())
                : "-";
    }
Selects an item from the list containing more than one item.

@param filteredList Will not be null or empty
@return An item from the list. If one can't be selected then return null
and the fallback selector (if provided) will be used instead.
stroom-util/src/main/java/stroom/util/io/capacity/AbstractSelector.java