code: void checkEntryParent()
    {
      if(parentList == null)
      {
        SIErrorException e = new SIErrorException(
          nls.getFormattedMessage(
            "INTERNAL_MESSAGING_ERROR_CWSIP0001",
            new Object[] {
              "com.ibm.ws.sib.processor.utils.linkedlist.Entry",
              "1:239:1.3" },
            null));
            
        // FFDC
        FFDCFilter.processException(
          e,
          "com.ibm.ws.sib.processor.utils.linkedlist.Entry.checkEntryParent",
          "1:246:1.3",
          this);
  
        SibTr.exception(tc, e);   
        SibTr.error(tc, "INTERNAL_MESSAGING_ERROR_CWSIP0001",
          new Object[] {
            "com.ibm.ws.sib.processor.utils.linkedlist.Entry",
            "1:253:1.3" });   
  
        if (tc.isEntryEnabled())
          SibTr.exit(tc, "checkEntryParent", e);
  
        throw e;
      }
    }
docs: Unsynchronized. Check that the parent list is not null and therefore the entry
  is still valid. Otherwise, throw a runtime exception