default boolean isDiskStoreId() {
    return false;
  }
The member that originated an update that is stored in the version information of a region entry,
or in the regions version vector.

A VersionMember could either be an InternalDistributedMember (for an in memory region), or a UUID
(for a persistent region).

VersionMembers should implement equals and hashcode.
geode-core/src/main/java/org/apache/geode/internal/cache/versions/VersionSource.java