code: @Override
      public List<String> introspect() {
          List<String> rc = super.introspect();
          String prefix = getClass().getSimpleName() + "@" + hashCode() + ": ";
          rc.add(prefix + "callback=" + callback);
          return rc;
      }
docs: /*
  @see com.ibm.ws.tcpchannel.internal.TCPBaseRequestContext#introspect()