public static String toHexString(byte[] src) {
        return toHexString(src, 0, src.length);
    }
@Test
    public void testToHexString() {
        assertThat(toHexString(new byte[] { 0 }), is("0"));
        assertThat(toHexString(new byte[] { 1 }), is("1"));
        assertThat(toHexString(new byte[] { 0, 0 }), is("0"));
        assertThat(toHexString(new byte[] { 1, 0 }), is("100"));
        assertThat(toHexString(EmptyArrays.EMPTY_BYTES), is(""));
    }