@Override
  public void writeMember(DiskStoreID member, DataOutput out) throws IOException {
    out.writeLong(member.getMostSignificantBits());
    out.writeLong(member.getLeastSignificantBits());

  }
For a persistent version tag, the member id should not be null, because we can't fill the
member id in later.
geode-core/src/main/java/org/apache/geode/internal/cache/versions/DiskVersionTag.java