code: @Override
      public String build() {
          StringBuilder sb = new StringBuilder();
          sb.append("CREATE CUSTOM INDEX ");
          sb.append(name).append(" ");
          String fullTable = keyspace == null ? table : keyspace + "." + table;
          sb.append(String.format("ON %s(%s) ", fullTable, column == null ? "" : column));
          sb.append("USING 'com.stratio.cassandra.lucene.Index' WITH OPTIONS = {");
          option(sb, "refresh_seconds", refreshSeconds);
          option(sb, "directory_path", directoryPath);
          option(sb, "ram_buffer_mb", ramBufferMb);
          option(sb, "max_merge_mb", maxMergeMb);
          option(sb, "max_cached_mb", maxCachedMb);
          option(sb, "indexing_threads", indexingThreads);
          option(sb, "indexing_queues_size", indexingQueuesSize);
          option(sb, "excluded_data_centers", excludedDataCenters);
          option(sb, "partitioner", partitioner);
          option(sb, "sparse", sparse);
          sb.append(String.format("'schema':'%s'}", schema));
          return sb.toString();
      }
docs: {@inheritDoc}