public T getValueOrElse(final T valueIfUnSet, final T valueIfNull) {
        if (!hasOverride) {
            return valueIfUnSet;
        } else if (value == null) {
            return valueIfNull;
        } else {
            return value;
        }
    }
Return the non-null override value or other if the override has explicitly been set to null/empty
stroom-core-shared/src/main/java/stroom/config/global/shared/OverrideValue.java