private static NodeResources.StorageType parseOptionalStorageType(String storageTypeString) {
        if (storageTypeString == null) return NodeResources.StorageType.getDefault();
        return switch (storageTypeString) {
            case "remote" -> NodeResources.StorageType.remote;
            case "local" -> NodeResources.StorageType.local;
            case "any" -> NodeResources.StorageType.any;
            default -> throw new IllegalArgumentException("Illegal storage-type value '" + storageTypeString +
                                                          "': Legal values are 'remote', 'local' 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