question: private static void writeExtraCodes ( int charOffset , byte [ ] bytes , byte extraCodeModifier , ExtraCodesStream extraCodes ) throws IOException { int numChars = extraCodes . getNumChars ( ) ; if ( numChars < charOffset ) { int fillChars = charOffset - numChars ; extraCodes . writeFill ( fillChars , INTERNATIONAL_EXTRA_PLACEHOLDER ) ; extraCodes . incrementNumChars ( fillChars ) ; } if ( bytes != null ) { extraCodes . write ( bytes ) ; extraCodes . incrementNumChars ( 1 ) ; } else { int lastIdx = extraCodes . getLength ( ) - 1 ; if ( lastIdx >= 0 ) { byte lastByte = extraCodes . get ( lastIdx ) ; lastByte += extraCodeModifier ; extraCodes . set ( lastIdx , lastByte ) ; } else { extraCodes . write ( extraCodeModifier ) ; extraCodes . setUnprintablePrefixLen ( 1 ) ; } } }
target:  Encodes the given extra code info in the given stream.