code: public void changeConnection(MEConnection downConn, MEConnection upConn)
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.entry(tc, "changeConnection", new Object[] { this, downConn, upConn} );
  
      if(downConn != null)
      {
        //remove the connection which has gone down
        removeConnection(downConn);
      }
        
      // The new connection will be created when needed
      
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.exit(tc, "changeConnection");
    }
docs: Indiciates a failed connection, a newly created connection, or a
  connection swap.  If upConn is null, then connection "downConn"
  has been removed from the system.  If downConn is null, then
  connection "upConn" has been added to the system.  Otherwise,
  "downConn" has been removed and replaced by "upConn".
  
  @param downConn A connection which has been removed from the system,
  or null.
  @param upConn A connection which has been added to the system, or
  null.