@Test
public void testConcat() {

  assertEquals("first/second", UrlSupport.concat("first", "second"));
  assertEquals("first/second", UrlSupport.concat("first", "/second"));
  assertEquals("first/second", UrlSupport.concat("first/", "//second"));
  assertEquals("/first/second", UrlSupport.concat("/first/", "//second"));
  assertEquals("/first", UrlSupport.concat("/", "first"));
  assertEquals("/first/", UrlSupport.concat("/", "first/", true));
  assertEquals("/first/", UrlSupport.concat("/", "first", true));
  assertEquals("first/second/", UrlSupport.concat("first", "second", true));
  assertEquals("first/second/", UrlSupport.concat("first", "second//", true));
  assertEquals("first/second/third", UrlSupport.concat("first", "second//", "third"));
  assertEquals("http://localhost:8080/first/second", UrlSupport.concat("http://localhost:8080", "first", "second"));
}