@Override
    public boolean equals(final Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        final CustomRollUpMask other = (CustomRollUpMask) obj;
        if (rolledUpTagPositions == null) {
            if (other.rolledUpTagPositions != null)
                return false;
        } else if (!rolledUpTagPositions.equals(other.rolledUpTagPositions))
            return false;
        return true;
    }
Holds a list of the positions of tags that are rolled up, zero based. The
position number is based on the alphanumeric sorted list of tag/field
names in the {@link StatisticStoreEntity}. Would use a SortedSet but that
is not supported by GWT. Must ensure the contents of this are sorted so
that when contains is called on lists of these objects it works
correctly.
stroom-legacy/stroom-legacy-model_6_1/src/main/java/stroom/legacy/model_6_1/CustomRollUpMask.java