@Nonnull
	public static String toHexString(int value) {
		return toHexString(value, -1, 1);
	}
@Test
	void testToHexString() {
		assertEquals("0", StringUtil.toHexString(0));
		assertEquals("ffffffff", StringUtil.toHexString(-1));
		assertEquals("10", StringUtil.toHexString(16));
		assertEquals("fffffff0", StringUtil.toHexString(-16));
	}