code: public void computeOrphan(Collection<Address> currentMembers) {
        if (!currentMembers.contains(getGlobalTransaction().getAddress())) {
           if (trace) log.tracef("This transaction's originator has left the cluster: %s", getGlobalTransaction());
           isOrphan = true;
        }
     }
docs: Check's if this transaction's originator is no longer part of the cluster (orphan transaction) and updates
  {@link #isOrphan()}.
  @param currentMembers The current members of the cache.