public com.thoughtworks.go.plugin.domain.common.Image fromJSON(String jsonString) {
        Map<String, String> json = GSON.fromJson(jsonString, new TypeToken<Map<String, String>>() {
        }.getType());
        String contentType = json.get("content_type");
        String data = json.get("data");
        return new com.thoughtworks.go.plugin.domain.common.Image(contentType, data, hash(contentType, data));
    }
@Test
    public void shouldDeserializeFromJSON() throws Exception {
        com.thoughtworks.go.plugin.domain.common.Image image = new ImageDeserializer().fromJSON("{\"content_type\":\"image/png\",\"data\":\"Zm9vYmEK\"}");
        assertThat(image.getContentType(), is("image/png"));
        assertThat(image.getData(), is("Zm9vYmEK"));
        assertThat(image.getHash(), is("a67bb2a01e8bbf37082c1288c7bfcc0e33bcc6ae65861df19b94e36600baa5a0"));
    }