code: void invalidate() {
  
          try {
  
              // Attempt to close delegate connection
              _delegateConnection.close();
  
          } catch (SIException exception) {
  
              FFDCFilter.processException(exception,
                                          "com.ibm.ws.sib.ra.impl.SibRaConnection.invalidate",
                                          "1:1875:1.41", this);
  
              if (TraceComponent.isAnyTracingEnabled() && TRACE.isEventEnabled()) {
                  SibTr.exception(this, TRACE, exception);
              }
          } catch (SIErrorException exception) {
  
              FFDCFilter.processException(exception,
                                          "com.ibm.ws.sib.ra.impl.SibRaConnection.invalidate",
                                          "1:1884:1.41", this);
  
              if (TraceComponent.isAnyTracingEnabled() && TRACE.isEventEnabled()) {
                  SibTr.exception(this, TRACE, exception);
              }
          }
  
          _valid = false;
  
      }
docs: Called by the managed connection during <code>cleanup</code>. In
  normal processing the connection handle is closed before the managed
  connection is cleaned up prior to going back in the pool. The calling of
  this method therefore indicates an error scenario.