public SamlServiceProviderBuilder sloEndpoint(SamlEndpoint sloEndpoint) {
        sloEndpoints.add(requireNonNull(sloEndpoint, "sloEndpoint"));
        return this;
    }
Adds a new single logout service endpoint of this service provider.
saml/src/main/java/com/linecorp/armeria/server/saml/SamlServiceProviderBuilder.java