private WALHeader buildWALHeader(Configuration conf, WALHeader.Builder builder)
    throws IOException {
    builder.setWriterClsName(getWriterClassName());
    builder.setCellCodecClsName(WALCellCodec.getWALCellCodecClass(conf).getName());
    return builder.build();
  }
Base class for Protobuf log writer.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/AbstractProtobufLogWriter.java