code: boolean isTransactionRolledBack () {
  
          final String methodName = "isTransactionRolledBack";
          if (TraceComponent.isAnyTracingEnabled() && TRACE.isEntryEnabled()) {
              SibTr.entry(this, TRACE, methodName);
          }
  
          // Default to true indicating a rollback 
          boolean isRolledBack = true;
          Boolean rolledBack = null;
  
          if (_lastXidUsed != null) {
              // Get hold of the state of the last transaction used by this xa resource
              // instance.
              synchronized (_transactionStates) {
  
                rolledBack = (Boolean) _transactionStates.remove (_lastXidUsed);
  
                if (TraceComponent.isAnyTracingEnabled() && TRACE.isDebugEnabled()) {
                  StringBuffer sb = new StringBuffer ("After removing the xid ");
                  sb.append (_lastXidUsed);
                  sb.append (" the hashtable of transactionStates now contains ");
                  sb.append (_transactionStates.size());
                  sb.append (" entries");
                  SibTr.debug (this, TRACE, sb.toString());
                }
             }
          } else {
  
            if (TraceComponent.isAnyTracingEnabled() && TRACE.isDebugEnabled()) {
              SibTr.debug (this, TRACE, "WARNING! No last Xid set");
            }
  
          }
  
  
          if (rolledBack != null) {
  
            isRolledBack = rolledBack.booleanValue();
  
          }
  
          if (TraceComponent.isAnyTracingEnabled() && TRACE.isEntryEnabled()) {
            SibTr.exit(this, TRACE, methodName, Boolean.valueOf(isRolledBack));
          }
  
          return isRolledBack;
  
      }
docs: Checks if the transaction was rolled back or not. If for some reason
  we could not obtain the transaction state then we return true indicating
  a rollback.
  
  @return true if the transaction was rolled back