try {
                        handler.execute(current);
                    } catch (Throwable e) {
                        current = new DefaultMultiCauseException("Error in unrecoverable error handler: " + handler, e, throwable);
                    }
                }
            }
        };
        this.hub = new MessageHub(completion.toString(), executorFactory, errorHandler);

	walkValues := []*Value{}
	for _, v := range b.Values {
		if v.Uses == 0 && v.removeable() {
			walkValues = append(walkValues, v)
		}
	}
	for len(walkValues) != 0 {
		v := walkValues[len(walkValues)-1]
		walkValues = walkValues[:len(walkValues)-1]
		if v.Uses == 0 && v.removeable() {
			walkValues = append(walkValues, v.Args...)
			v.reset(OpInvalid)
		}
	}
	return true
}

		// which can be modified in another goroutine when apiserver request times out.
		// For example authentication filter modifies request's headers,
		// This can cause apiserver to crash with unrecoverable fatal error.
		// More info about concurrent read and write for maps: https://golang.org/doc/go1.6#runtime
		"userAgent", rl.userAgent,
		"audit-ID", auditID,
		"srcIP", rl.req.RemoteAddr,
	}

	zero  uint64
	fatal func(msg string)
}

func (n *nonceGenerator) next(b []byte) {
	incrementingNonce := n.nonce.Add(1)
	if incrementingNonce <= n.zero {
		// this should never happen, and is unrecoverable if it does
		n.fatal("aes-gcm detected nonce overflow - cryptographic wear out has occurred")
	}
	binary.LittleEndian.PutUint64(b, incrementingNonce)
}

func die(msg string) {