@Test
public void testIsTgz() {

    assertTrue(VirtualDirTgz.isTgz("test_archive.tar.gz"));
    assertTrue(VirtualDirTgz.isTgz("test_archive.tgz"));
    assertFalse(VirtualDirTgz.isTgz("test_archive.tar"));
    assertFalse(VirtualDirTgz.isTgz("test_archive.exe"));
    assertFalse(VirtualDirTgz.isTgz("test_archive"));
}