question: public void testConstructorSignBytesPositive1 ( ) { byte aBytes [ ] = { 12 , 56 , 100 , - 2 , - 76 , 89 , 45 , 91 , 3 , - 15 } ; int aSign = 1 ; byte rBytes [ ] = { 12 , 56 , 100 , - 2 , - 76 , 89 , 45 , 91 , 3 , - 15 } ; BigInteger aNumber = new BigInteger ( aSign , aBytes ) ; byte resBytes [ ] = new byte [ rBytes . length ] ; resBytes = aNumber . toByteArray ( ) ; for ( int i = 0 ; i < resBytes . length ; i ++ ) { assertTrue ( resBytes [ i ] == rBytes [ i ] ) ; } assertEquals ( "incorrect sign" , 1 , aNumber . signum ( ) ) ; }
target:  Create a positive number from a sign and an array of bytes. The number fits in an array of integers. The most significant byte is positive.