class PerfstatDisk {

    private static final Perfstat PERF = Perfstat.INSTANCE;

    private PerfstatDisk() {
    }

    /**
     * Queries perfstat_disk for per-disk usage statistics
     *
     * @return an array of usage statistics
     */
    public static perfstat_disk_t[] queryDiskStats() {<FILL_FUNCTION_BODY>}
}

        perfstat_disk_t diskStats = new perfstat_disk_t();
        // With null, null, ..., 0, returns total # of elements
        int total = PERF.perfstat_disk(null, null, diskStats.size(), 0);
        if (total > 0) {
            perfstat_disk_t[] statp = (perfstat_disk_t[]) diskStats.toArray(total);
            perfstat_id_t firstdiskStats = new perfstat_id_t(); // name is ""
            int ret = PERF.perfstat_disk(firstdiskStats, statp, diskStats.size(), total);
            if (ret > 0) {
                return statp;
            }
        }
        return new perfstat_disk_t[0];
    
<no_super_class>