@Data  @AllArgsConstructor  @NoArgsConstructor
	static class Person implements Externalizable {
		String firstName;
		String lastName;
		LocalDate birthDate;
		byte[] image;

		@Override  @SneakyThrows
		public void writeExternal (ObjectOutput out) {
			out.writeUTF(firstName);
			out.writeUTF(lastName);
			out.writeShort(birthDate.getYear());
			out.writeByte(birthDate.getMonthValue());
			out.writeByte(birthDate.getDayOfMonth());
			out.writeInt(image.length);
			out.write(image);
		}

		@Override  @SneakyThrows
		public void readExternal(ObjectInput in) {
			firstName = in.readUTF();
			lastName = in.readUTF();
			birthDate = LocalDate.of(in.readShort(), in.readUnsignedByte(), in.readUnsignedByte());
			int imageLength = in.readInt();
			image = new byte[imageLength];
			in.readFully(image);
		}
	}

	@Test
	void testCustomObjects () {
		var p = new Person("John", "Smith", LocalDate.of(1926, 4, 15), "some random bytes as photo image".getBytes());

		var w = new FastByteArrayOutputStream();
		p.writeExternal(w);
		p.writeExternal(w);
		p.writeExternal(w);
		assertEquals("00044a6f686e0005536d6974680786040f00000020736f6d652072616e646f6d2062797465732061732070686f746f20696d616765".repeat(3), toHexString(w.array, 0, w.length));
		assertEquals(w.position, w.length);
		assertTrue(w.length <= w.array.length);

		var r = new FastByteArrayInputStream(w.array, 0, w.length);
		var p2 = new Person();

		p2.readExternal(r);
		assertEquals(p, p2);
		assertEquals(p.toString(), p2.toString());

		p2.readExternal(r);
		assertEquals(p, p2);
		assertEquals(p.toString(), p2.toString());

		p2.readExternal(r);
		assertEquals(p, p2);
		assertEquals(p.toString(), p2.toString());
	}