public PartitionId createNewPartition(List<MockDataNodeId> dataNodes, int mountPathIndexToUse) {
    MockPartitionId partitionId =
        new MockPartitionId(partitions.size(), DEFAULT_PARTITION_CLASS, dataNodes, mountPathIndexToUse);
    partitions.put((long) partitions.size(), partitionId);
    // make partitionSelectionHelper re-populate internal maps because new replicas(partition) are added
    partitionSelectionHelper.onReplicaAddedOrRemoved(partitionId.getReplicaIds(), Collections.emptyList());
    return partitionId;
  }
Create a new partition at given mount path on given nodes.
@param dataNodes the nodes on which replicas of new partition should reside.
@param mountPathIndexToUse the mount path index to use when creating new partition
@return new {@link PartitionId}
ambry-test-utils/src/main/java/com/github/ambry/clustermap/MockClusterMap.java