private boolean hasHeartbeatExpired() {
    return EnvironmentEdgeManager.currentTime() - lastHeartBeat.get() >= getTimeout();
  }
Constructor for region lock(s).
@param lockAcquireLatch if not null, the latch is decreased when lock is acquired. Useful for
                        locks acquired locally from master process.
@throws IllegalArgumentException if all regions are not from same table.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/locking/LockProcedure.java