question: public boolean ackNextChunkId ( String id ) { if ( state . isTerminated ( ) ) return false ; else if ( id . equals ( chunkid ) ) { return true ; } else { if ( ! allowOtherChunksInBetween ( id ) ) { if ( state . isDone ( ) ) { if ( ! isTerminated ( ) ) terminate ( ) ; return false ; } else { throw new PngjInputException ( "Unexpected chunk " + id + " while " + chunkid + " set is not done" ) ; } } else return true ; } }
target:  This will be called by the owner to report us the next chunk to come. We can make our own internal changes and checks. This returns true if we acknowledge the next chunk as part of this set