code: protected final void addIllegalFieldPointer (int byteNumber) {
          final FieldPointerSenseKeySpecificData fp = new FieldPointerSenseKeySpecificData(true,// senseKeySpecificDataValid
          true,// commandData (i.e. invalid field in CDB)
          false,// bitPointerValid
          0,// bitPointer
          byteNumber);// fieldPointer
          addIllegalFieldPointer(fp);
      }
docs: Adds an instance {@link FieldPointerSenseKeySpecificData}, which specifies an illegal field by the position of
  its first byte, to {@link #illegalFieldPointers}.
  
  @param byteNumber index of the first byte of the illegal field