String extractTemplate(String templateLocation) {
    try {
      URL url = Resources.getResource(templateLocation);
      return Resources.toString(url, StandardCharsets.UTF_8);
    } catch (IOException | IllegalArgumentException e) {
      throw new IllegalStateException("Cannot read the template " + templateLocation, e);
    }
  }
@Test
  public void extract_nonexistant_template() {
    assertThrows(IllegalStateException.class, () -> underTest.extractTemplate("not-there"));
  }