public void testConcatPath_siblingDiretory_returnsSibling() {
   String ret = Utility.concatPath("root", "../dummy/content.opf");
   Assert.assertEquals("dummy/content.opf", ret);
 }
 public void testConcatPath_subdiretory_returnIncludesSubdir() {
   String ret = Utility.concatPath("root", "dummy/content.opf");
   Assert.assertEquals("root/dummy/content.opf", ret);
 }
 public void testConcatPath_absolute_returnsAbsolute() {
   String ret = Utility.concatPath("root", "/content.opf");
   Assert.assertEquals("content.opf", ret);
 }
 public void testConcatPath_basic_returnSuccess() {
   String ret = Utility.concatPath("root", "content.opf");
   Assert.assertEquals("root/content.opf", ret);
 }