### Question:
Hex { public static String s1(int v) { char[] result = new char[3]; if (v < 0) { result[0] = '-'; v = -v; } else { result[0] = '+'; } for (int i = 0; i < 2; i++) { result[2 - i] = Character.forDigit(v & 0x0f, 16); v >>= 4; } return new String(result); } private  Hex(); static String u8(long v); static String u4(int v); static String u3(int v); static String u2(int v); static String u2or4(int v); static String u1(int v); static String uNibble(int v); static String s8(long v); static String s4(int v); static String s2(int v); static String s1(int v); static String dump(byte[] arr, int offset, int length,
                              int outOffset, int bpl, int addressLength);  }### Answer:
@Test public void testS1() { Assert.assertEquals("+00", Hex.s1(0)); Assert.assertEquals("-00", Hex.s1(-2147483648)); Assert.assertEquals("+7b", Hex.s1(123)); Assert.assertEquals("+d2", Hex.s1(1234567890)); }