code: public alluxio.grpc.TierList getAddedBlocksOnTiersOrDefault(
        java.lang.String key,
        alluxio.grpc.TierList defaultValue) {
      if (key == null) { throw new java.lang.NullPointerException(); }
      java.util.Map<java.lang.String, alluxio.grpc.TierList> map =
          internalGetAddedBlocksOnTiers().getMap();
      return map.containsKey(key) ? map.get(key) : defaultValue;
    }
docs: <pre>
  * the map of added blocks on all tiers
  </pre>
  
  <code>map&lt;string, .alluxio.grpc.block.TierList&gt; addedBlocksOnTiers = 4;</code>