// Then
        assertEquals(expiration, result);
        verify(mockReferralData).getExpiration();
    }

    @Test
    @DisplayName("Should get next referral")
    void testNext() {
        // Given
        DfsReferralData nextReferral = mock(DfsReferralData.class);
        when(mockReferralData.next()).thenReturn(nextReferral);

        // When

            assertDoesNotThrow(() -> concreteImplementation.stripPathConsumed(0));
        }

        @Test
        @DisplayName("Should return next referral data")
        void testNext() {
            // Test with mock
            when(mockReferralData.next()).thenReturn(mockReferralData);
            DfsReferralDataInternal next = mockReferralData.next();
            assertSame(mockReferralData, next);

            assertEquals(second, third.next());
            assertEquals(referralData, second.next());
        }

        @Test
        @DisplayName("Should handle next() correctly")
        void testNext() {
            DfsReferralDataImpl second = new DfsReferralDataImpl();
            referralData.append(second);

            DfsReferralDataImpl next = referralData.next();
            assertSame(second, next);