question: public void testCase22 ( ) { byte bBytes [ ] = { 120 , 34 , 78 , - 23 , - 111 , 45 , 127 , 23 , 45 , - 3 } ; byte rBytes [ ] = { 120 , 34 , 78 , - 23 , - 111 , 45 , 127 , 23 , 45 , - 3 } ; int bSign = - 1 ; BigInteger aNumber = BigInteger . ZERO ; BigInteger bNumber = new BigInteger ( bSign , bBytes ) ; BigInteger result = aNumber . subtract ( bNumber ) ; byte resBytes [ ] = new byte [ rBytes . length ] ; resBytes = result . toByteArray ( ) ; for ( int i = 0 ; i < resBytes . length ; i ++ ) { assertTrue ( resBytes [ i ] == rBytes [ i ] ) ; } assertEquals ( 1 , result . signum ( ) ) ; }
target:  Subtract a number from ZERO. The number is negative.