We are currently using a RangeSet to track various identifiers in the FE/BE conversation. These identifiers are UnsignedLongs, hence come from a discrete set. Unfortunately default TreeRangeSet is designed to work in continuum, forcing us to use half-closed ranges, as evidenced https://git.opendaylight.org/gerrit/58800.

This is not really efficient as we could do better with a dedicated discrete RangeSet implementation. Explore our options and come up with a better solution.

Note this does not have to impact serialization format, as we can still translate to/from normal RangeSets.