SamlPortConfigAutoFiller toAutoFiller() {
        return new SamlPortConfigAutoFiller(copyOf(this));
    }
Converts this builder to a {@link SamlPortConfigAutoFiller} in order to fill unspecified values
after the server started.
saml/src/main/java/com/linecorp/armeria/server/saml/SamlPortConfigBuilder.java