protected void postInsertHook(boolean usedFreeSlot) {
    if (usedFreeSlot) {
      hashIndexSetProperties.free--;
    } else {
      // we used a removeToken
      hashIndexSetProperties.removedTokens--;
    }
    hashIndexSetProperties.size++;
  }
After insert, allows for calculating metadata
geode-core/src/main/java/org/apache/geode/cache/query/internal/index/HashIndexSet.java