docs: public MigrationInfo setActiveMigration(MigrationInfo migrationInfo) {
          partitionServiceLock.lock();
          try {
              if (activeMigrationInfo == null) {
                  activeMigrationInfo = migrationInfo;
                  return null;
              }
              if (!activeMigrationInfo.equals(migrationInfo)) {
                  if (logger.isFineEnabled()) {
                      logger.fine("Active migration is not set: " + migrationInfo
                              + ". Existing active migration: " + activeMigrationInfo);
                  }
              }
              return activeMigrationInfo;
          } finally {
              partitionServiceLock.unlock();
          }
      }