public static SamlNameIdPolicy ofCreatable(SamlNameIdFormat format) {
        return of(format, true);
    }
Returns a {@link SamlNameIdPolicy} with the specified {@link SamlNameIdFormat} and
{@code isCreatable = true}.
saml/src/main/java/com/linecorp/armeria/server/saml/SamlNameIdPolicy.java