@Test
public void importOptionsTest() {

    ImportOptions options = new ImportOptions();
    Set<String> extensionsList = Sets.newHashSet("loadFoo", "loadBar");
    options.setExtensions(extensionsList);
    assertEquals(Boolean.FALSE, options.withNoExtension());
    options.addExtension("loadBar");
    assertEquals(2, (int) options.getExtensions().map(Set::size).orElse(-1));
}