TextUtils { public static boolean isEmpty(String url) { return url == null || "".equals(url.trim()); }  static boolean isEmpty(String url); static String getLastSevenNumbers(String uniqueId); @NonNull static String lintUrl(String url); static String truncateByDoubleColons(String source, int level);  }
@Test public void should_be_true_when_url_is_null() throws Exception { assertThat(TextUtils.isEmpty(null), is(true)); }
@Test public void should_be_true_when_url_is_empty() throws Exception { assertThat(TextUtils.isEmpty(" "), is(true)); }
@Test public void should_be_false_when_url_is_not_empty() throws Exception { assertThat(TextUtils.isEmpty("primero"), is(false)); }