question: public void copyResiduals ( byte [ ] source , int targetPosition , int targetSize ) { int unitSize = source . length ; if ( unitSize < targetSize ) { int targetStart = ( targetSize - unitSize ) / 2 ; System . arraycopy ( source , 0 , residuals , targetPosition + targetStart , source . length ) ; } else { int sourcePosition = ( unitSize - targetSize ) / 2 ; System . arraycopy ( source , sourcePosition , residuals , targetPosition , targetSize ) ; } }
target:  Copies the information in the given unit to the array of residuals, starting at the given index, up until targetSize chars.