if (type.isInstance(this)) {
                return type.cast(this);
            }
            throw new ClassCastException("Cannot unwrap to " + type.getName());
        }
    }

    static class SelfRenewingCreds extends BaseCreds {
        @Override
        public CredentialsInternal renew() {
            // Returns itself as the renewed credentials
            return this;
        }
    }