public boolean isDynamic() {
    return isDynamic;
  }
Locks the Llap Cluster for configuration change for the given time window.
@param windowStart The beginning of the time window when no other configuration change is allowed.
@param windowEnd The end of the time window when no other configuration change is allowed.
@return The result of the change (success if the lock is succeeded, and the next possible
configuration change time
llap-client/src/java/org/apache/hadoop/hive/llap/registry/impl/LlapRegistryService.java