@Test
 public void shouldReturnInvalidRefreshToken() {
   assertEquals(false, refreshToken.isValid());
 }
 @Test
 public void shouldReturnInvalidRefreshTokenWithErrorReason() {
   refreshToken.setErrorReason("errorReason");
   assertEquals("errorReason", refreshToken.getErrorReason());
   assertEquals(false, refreshToken.isValid());
 }
 @Test
 public void shouldReturnValidRefreshToken() {
   refreshToken.setRefreshToken("refreshToken");
   assertEquals("refreshToken", refreshToken.getRefreshToken());
   assertEquals(true, refreshToken.isValid());
 }