### Question:
Utils { public static String normalizeBaseUrl(String url) { if (url == null || url.length() == 0) { return url; } if (url.endsWith("/")) { return url; } return url + "/"; } private  Utils(); static T checkNotNull(T object, String message); static void checkArgument(boolean condition, String message); static int headerToInt(com.squareup.okhttp.Headers headers, String key); static String normalizeBaseUrl(String url); static String joinString(CharSequence delimiter, Iterable tokens);  }### Answer:
@Test public void normalizeBaseUrlShouldAddTrailingSlashIfMissing() { String url = "http: assertThat(Utils.normalizeBaseUrl(url), is(url + "/")); }
@Test public void normalizeBaseUrlShouldNotNormalizeEmptyString() { String url = ""; assertThat(Utils.normalizeBaseUrl(url), is("")); }
@Test public void normalizeBaseUrlShouldNotNormalizeNullString() { String url = null; assertThat(Utils.normalizeBaseUrl(url), is(nullValue())); }