@Override
      public void run() {
        while (!stopped) {
          // keep triggering chunk retirement
          mslab.copyCellInto(cellToCopyInto);
        }
      }
After mslab close, jumboChunk is removed from {@link ChunkCreator#chunkIdMap} but because
dataChunk is recycled to pool so it is still in {@link ChunkCreator#chunkIdMap}.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMemStoreLAB.java