return Arrays.asList(type.getInterfaces());
          }

          @Override
          @Nullable Class<?> getSuperclass(Class<?> type) {
            return type.getSuperclass();
          }
        };

    /** For just classes, we don't have to traverse interfaces. */
    final TypeCollector<K> classesOnly() {

        // We can't easily test the actual functionality without complex mocking
        // but we can verify the class structure
        assertNotNull(crawlerLogHelper);
        assertTrue(CrawlerLogHelper.class.getSuperclass().getSimpleName().contains("LogHelper"));
    }

            if (containsMethod(current, method)) {
                classesContainingMethod.add(current)
            } else {
                break
            }
            current = current.getSuperclass()
        }

        for (int i = classesContainingMethod.size() - 1; i > 0; --i) {
            current = classesContainingMethod.get(i)
            if (!isInternal(current)) {

        }
    }

    @Test
    public void test_inheritance() {
        // Verify that SystemUtil extends org.codelibs.core.lang.SystemUtil
        Class<?> superClass = SystemUtil.class.getSuperclass();
        assertEquals("Should extend org.codelibs.core.lang.SystemUtil", "org.codelibs.core.lang.SystemUtil", superClass.getName());
    }

    @Test
    public void test_constants_reference() {

        while (clazz != null) {
            try {
                return clazz.getDeclaredField(fieldName);
            } catch (final NoSuchFieldException e) {
                clazz = clazz.getSuperclass();
            }
        }
        throw new RuntimeException("Field not found: " + fieldName);
    }

  public void testGetGenericSuperclass_withSuperclass() {
    TypeToken<? super ArrayList<String>> superToken =
        new TypeToken<ArrayList<String>>() {}.getGenericSuperclass();
    assertEquals(ArrayList.class.getSuperclass(), superToken.getRawType());
    assertEquals(
        String.class, ((ParameterizedType) superToken.getType()).getActualTypeArguments()[0]);

  public void testGetGenericSuperclass_withSuperclass() {
    TypeToken<? super ArrayList<String>> superToken =
        new TypeToken<ArrayList<String>>() {}.getGenericSuperclass();
    assertEquals(ArrayList.class.getSuperclass(), superToken.getRawType());
    assertEquals(
        String.class, ((ParameterizedType) superToken.getType()).getActualTypeArguments()[0]);