code: private int getAdditionalSenseLength () {
          int additionalSenseLength = 0;
          if (senseDataDescriptors != null) {
              for (int i = 0; i < senseDataDescriptors.length; ++i)
                  if (senseDataDescriptors[i] != null) additionalSenseLength += senseDataDescriptors[i].size();
          }
          return additionalSenseLength;
      }
docs: Returns the value of the ADDITIONAL SENSE LENGTH field.
  <p>
  This is the total length of all included {@link SenseDataDescriptor} objects.
  
  @return the value of the ADDITIONAL SENSE LENGTH field