#fixed code
                              @ManagedMetric(description = "Total Disk Space used")
  public long getTotalDiskUsed() {
    return convertPotentialLong(parseStorageTotals().get("hdd").get("used"));
  }
#vulnerable code 
                              @ManagedMetric(description = "Total Disk Space used")
  public long getTotalDiskUsed() {
    return (Long) parseStorageTotals().get("hdd").get("used");
  } 
                            #location 3 
                            #vulnerability type NULL_DEREFERENCE