question: public static byte [ ] copy ( byte [ ] source , byte [ ] target ) { int len = source . length ; if ( len > target . length ) { target = new byte [ len ] ; } System . arraycopy ( source , 0 , target , 0 , len ) ; return target ; }
target:  Copy the contents of the source array to the target array. If the size if the target array is too small, a larger array is created.