question: public byte [ ] toByteArray ( ) { int totalLen = _pastLen + _currBlockPtr ; if ( totalLen == 0 ) { return NO_BYTES ; } byte [ ] result = new byte [ totalLen ] ; int offset = 0 ; for ( byte [ ] block : _pastBlocks ) { int len = block . length ; System . arraycopy ( block , 0 , result , offset , len ) ; offset += len ; } System . arraycopy ( _currBlock , 0 , result , offset , _currBlockPtr ) ; offset += _currBlockPtr ; if ( offset != totalLen ) { throw new RuntimeException ( "Internal error: total len assumed to be " + totalLen + ", copied " + offset + " bytes" ) ; } if ( ! _pastBlocks . isEmpty ( ) ) { reset ( ) ; } return result ; }
target:  Method called when results are finalized and we can get the full aggregated result buffer to return to the caller