code: public Config addMerkleTreeConfig(MerkleTreeConfig merkleTreeConfig) {
          final String mapName = merkleTreeConfig.getMapName();
          if (StringUtil.isNullOrEmpty(mapName)) {
              throw new IllegalArgumentException("Merkle tree config must define a map name");
          }
          mapMerkleTreeConfigs.put(mapName, merkleTreeConfig);
          return this;
      }
docs: Adds the merkle tree configuration.
  The returned {@link MerkleTreeConfig#getMapName()} may be a
  pattern with which the configuration will be obtained in the future.
  
  @param merkleTreeConfig the merkle tree configuration
  @return this config instance
  @throws IllegalArgumentException if the {@link MerkleTreeConfig#getMapName()}
  is empty