@Override
    public String getSharedSecret() {
        if (secret != null) {
            return secret;
        }
        synchronized (mutex) {
            if (secret == null) {
                if (getCache().containsKey(SHARED_SECRET_KEY)) {
                    secret = String.valueOf(getCache().get(SHARED_SECRET_KEY));
                } else {
                    secret = UUID.randomUUID().toString();
                    getCache().put(SHARED_SECRET_KEY, secret);
                }
            }
            return secret;
        }
    }
@see io.apiman.common.auth.ISharedSecretSource#getSharedSecret()
manager/api/ispn/src/main/java/io/apiman/manager/api/ispn/InfinispanSharedSecretSource.java