code: private void emergencyClose() {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "emergencyClose");
  
          try {
              if (coreConsumerSession != null)
                  coreConsumerSession.close();
          } catch (SIException e) {
              // No FFDC code needed
              // d238447 FFDC review - ok
              FFDCFilter.processException(e, "com.ibm.ws.sib.api.jms.impl.JmsMsgConsumerImpl", "emergencyClose#1", this);
          } finally {
              // d245254 - set the consumer session to null so that subsequent stop/close calls
              // don't generate exceptions.
              coreConsumerSession = null;
              // set the closed flag so that the majority of methods calls will generate an appopriate exception
              // Note that this is not synchronized on the closeLock as we don't want to risk this blocking.
              closed = true;
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "emergencyClose");
      }
docs: Provides a minimalist abrupt shutdown of the consumer.
  This method is used from the async delivery code, and its
  primary purpose is to prevent further message loss in the
  face of unrecoverable errors during message delivery.