public String toDataURI() {
        return "data:" + contentType + ";base64," + data;
    }
@Test
    void convertsToDataUri() {
        String encodedString = Base64.getEncoder().encodeToString("asdf".getBytes(StandardCharsets.UTF_8));
        String dataURI = new Image("image/png", encodedString, "sha-256").toDataURI();
        assertThat(dataURI, is("data:image/png;base64," + encodedString));
    }