@JsonCreator
    public static BingTile fromCoordinates(
            @JsonProperty("x") int x,
            @JsonProperty("y") int y,
            @JsonProperty("zoom") int zoomLevel)
    {
        return new BingTile(x, y, zoomLevel);
    }
@Test
    public void testSerialization()
            throws Exception
    {
        ObjectMapper objectMapper = new ObjectMapper();
        BingTile tile = fromCoordinates(1, 2, 3);
        String json = objectMapper.writeValueAsString(tile);
        assertEquals("{\"x\":1,\"y\":2,\"zoom\":3}", json);
        assertEquals(tile, objectMapper.readerFor(BingTile.class).readValue(json));
    }