@Override
    public boolean equals(Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || getClass() != o.getClass()) {
        return false;
      }
      DiskConfig that = (DiskConfig) o;
      return diskCapacityInBytes == that.diskCapacityInBytes && state == that.state && Objects.equals(replicaConfigs,
          that.replicaConfigs);
    }
@return a map from partition id to {@link ReplicaConfig} for all the replicas on the server.
        This map is mutable.
ambry-api/src/main/java/com/github/ambry/clustermap/DataNodeConfig.java