private void generateSharedEventOffset(TXState txState) {
    assert farSideEventOffset == -1;
    generateNearSideEventOffset(txState);
    farSideEventOffset = nearSideEventOffset;
  }
Generate the offset for an eventId that will be used for both a farside and nearside op for
this entry.

@since GemFire 5.7
geode-core/src/main/java/org/apache/geode/internal/cache/TXEntryState.java