private static NodeResources.Architecture parseOptionalArchitecture(String architecture) {
        if (architecture == null) return NodeResources.Architecture.getDefault();
        return switch (architecture) {
            case "x86_64" -> NodeResources.Architecture.x86_64;
            case "arm64" -> NodeResources.Architecture.arm64;
            case "any" -> NodeResources.Architecture.any;
            default -> throw new IllegalArgumentException("Illegal architecture value '" + architecture +
                                                          "': Legal values are 'x86_64', 'arm64' and 'any')");
        };
    }
Returns whether the count attribute was present on the {@code <nodes>} element.
config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/NodesSpecification.java