@Override
    public String chooseEngineClientAlias(String[] keyType, Principal[] issuers, SSLEngine engine) {
        return delegate.chooseEngineClientAlias(keyType, issuers, engine);
    }
{@link X509ExtendedKeyManager} chooses the given alias for the server side.
spring/boot3-autoconfigure/src/main/java/com/linecorp/armeria/internal/spring/CustomAliasX509ExtendedKeyManager.java