public int getGroupId() {
    return groupId;
  }
This class tracks for a current state for {@link com.github.ambry.replication.ReplicaThread.RemoteReplicaGroup}
  for continuous replication cycle.

  {@link #groupId} group id assigned to remote replica group
  {@link #remoteReplicaGroup} group for which we have created this tracker
  {@link #inflightReplicaTrackers} replicas that are currently present in {@link #remoteReplicaGroup}
  {@link #iterations} total number of iterations for the remote replica group with {@link #groupId} group id
ambry-replication/src/main/java/com/github/ambry/replication/continuous/GroupTracker.java