### Question:
AptUtils { public static boolean isExternalLink( String link ) { return DoxiaUtils.isExternalLink( link ); } private  AptUtils(); static String encodeFragment( String text ); static boolean isExternalLink( String link ); static boolean isInternalLink( String link ); static boolean isLocalLink( String link ); static String linkToKey( String text ); static String encodeAnchor( String id );  }### Answer:
@Test public void testIsExternalLink() { String link = "http: assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "https: assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "HTTPS: assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "ftp:/maven.apache.org/"; assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "mailto:maven@apache.org"; assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "file:/index.html"; assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "resource_type: assertTrue( "Should be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "index.html"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "example.pdf"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "./index.html"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "../index.html"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "file:\\index.html"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); link = ".\\index.html"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); link = "..\\index.html"; assertFalse( "Should NOT be an external link: " + link, AptUtils.isExternalLink( link ) ); }