public static Uuid random() {
        while (true) {
            // Uuid.randomUuid does not generate Uuids whose string representation starts with a
            // dash.
            Uuid uuid = Uuid.randomUuid();
            if (!DirectoryId.reserved(uuid)) {
                return uuid;
            }
        }
    }
Static factory to generate a directory ID.

This will not generate a reserved UUID (first 100), or one whose string representation
starts with a dash ("-")
server-common/src/main/java/org/apache/kafka/common/DirectoryId.java