### Question:
GravatarUtil { public static String getGravatarUrl(UserPrincipal userPrincipal) { return getGravatarUrl(userPrincipal.getEmail()); } private  GravatarUtil(); static String generateHash(String emailAddress); static String getGravatarUrl(UserPrincipal userPrincipal); static String getGravatarUrl(UserPrincipal userPrincipal, int size); static String getGravatarUrl(String emailAddress); static String getGravatarUrl(String emailAddress, int size);  }### Answer:
@Test public void getGravatarUrlFromPrincipalTest() { UserPrincipal user = mock(UserPrincipal.class); when(user.getEmail()).thenReturn("admin@example.com"); Assert.assertEquals("https: }
@Test public void getGravatarUrlFromPrincipalSizeTest() { UserPrincipal user = mock(UserPrincipal.class); when(user.getEmail()).thenReturn("admin@example.com"); Assert.assertEquals("https: }
@Test public void getGravatarUrlTest() { Assert.assertEquals("https: String s = null; Assert.assertEquals("https: }
@Test public void getGravatarUrlSizeTest() { Assert.assertEquals("https: String s = null; Assert.assertEquals("https: }