public void remove() {
      // NOTE: it would seem logical that entry removal will semantically mean
      // removing the matching pair <k,v>, but the JDK always removes by key,
      // even when the value has changed.
      _ss.removeKey();
    }
Keys as a long array.  Array may be zero-padded if keys are concurrently deleted.
jctools-core/src/main/java/org/jctools/maps/NonBlockingHashMapLong.java