question: private void replace ( final char [ ] revA , final char [ ] revB , final DiffBlock curA , final DiffBlock curB ) throws UnsupportedEncodingException { String text = copy ( revB , curB . getRevBStart ( ) , curB . getRevBEnd ( ) ) ; DiffPart action = new DiffPart ( DiffAction . REPLACE ) ; action . setStart ( version . length ( ) ) ; codecData . checkBlocksizeS ( version . length ( ) ) ; action . setLength ( curA . getRevAEnd ( ) - curA . getRevAStart ( ) ) ; codecData . checkBlocksizeE ( action . getLength ( ) ) ; action . setText ( text ) ; codecData . checkBlocksizeL ( text . getBytes ( WIKIPEDIA_ENCODING ) . length ) ; diff . add ( action ) ; version . append ( text ) ; }
target:  Creates a replace operation.