@Test
public void testImportXls_MissingKeys_DoNothing() throws IOException, URISyntaxException {

  // - preparation
  final Path propertiesRootDirectory= this.tmpFolder.getRoot().toPath();
  final Set<File> resourceBundleFiles= ImmutableSet.of(
    copyResourceToTmp("i18n/messages.properties"),
    copyResourceToTmp("i18n/messages_de.properties"));
  final FileMatcher fileMatcher= this.createFileMatcher(propertiesRootDirectory, resourceBundleFiles);
  final File xlsFile= new File(Resources.getResource("i18n_line_deleted.xlsx").toURI());
  // - test
  XlsImExporter.importXls(fileMatcher, xlsFile, UTF_8, MissingKeyAction.NOTHING);
  // - verification
  final Path[] writtenResourceBundleFiles = Files.list(propertiesRootDirectory.resolve("i18n")).toArray(Path[]::new);
  assertThat(writtenResourceBundleFiles).containsOnly(
    propertiesRootDirectory.resolve("i18n/messages.properties"),
    propertiesRootDirectory.resolve("i18n/messages_de.properties")
  );
  assertThat(propertiesRootDirectory.resolve("i18n").resolve("messages.properties").toFile())
    .hasContent(""
      + "ok = OK\n"
      + "cancel = Cancel\n"
      + "\n");
  assertThat(propertiesRootDirectory.resolve("i18n").resolve("messages_de.properties").toFile())
    .hasContent(""
      + "ok = OK\n"
      + "cancel = Abbrechen\n"
      + "\n");
}