@Test
public void hex() {

    assertEquals("", Strings.hex(new byte[]{}));
    assertEquals("00", Strings.hex(new byte[]{ 0 }));
    assertEquals("0001", Strings.hex(new byte[]{ 0, 1 }));
    assertEquals("00017F80FF", Strings.hex(new byte[]{ 0, 1, 127, (byte)128, (byte)255}));
}