private synchronized long startOperation() {
      logNewOperation();
      currentVersionOpCount++;
      return membershipVersion;
    }
this method must be invoked at the start of every operation that can modify the state of
resource. The return value must be recorded and sent to the advisor in an endOperation
message when messages for the operation have been put in the DistributionManager's outgoing
"queue".

@return the current membership version for this advisor
@since GemFire 5.1
geode-core/src/main/java/org/apache/geode/distributed/internal/DistributionAdvisor.java