void write(DataOutput os) throws IOException {
    DataInputOutputUtil.writeINT(os, myIndexVersion);
    DataInputOutputUtil.writeINT(os, myCommonIndicesVersion);
    DataInputOutputUtil.writeTIME(os, myVfsCreationStamp);
    DataInputOutputUtil.writeTIME(os, myModificationCount);
  }
void write(DataOutput os)