question: public void testCase18 ( ) { byte aBytes [ ] = { 120 , 34 , 78 , - 23 , - 111 , 45 , 127 , 23 , 45 , - 3 } ; byte bBytes [ ] = { 0 } ; byte rBytes [ ] = { 120 , 34 , 78 , - 23 , - 111 , 45 , 127 , 23 , 45 , - 3 } ; int aSign = 1 ; int bSign = 0 ; BigInteger aNumber = new BigInteger ( aSign , aBytes ) ; 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 zero from a number. The number is positive.