public void closeAfterLeasesExpire() {
    this.stopRequested = true;
  }
Shuts down this lease instance when all outstanding leases expire. Like {@link #close()} but
rather than violently end all leases, waits first on extant leases to finish. Use this method
if the lease holders could lose data, leak locks, etc. Presumes client has shutdown allocation
of new leases.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/LeaseManager.java