assertThat(generator.generateFresh(Currency.class)).isNotNull();
    assertThat(generator.generateFresh(Currency.class)).isNotNull();
  }

  public void testNulls() throws Exception {
    new ClassSanityTester()
        .setDefault(Method.class, FreshValueGeneratorTest.class.getDeclaredMethod("testNulls"))
        .testNulls(FreshValueGenerator.class);
  }

        if (configId == null) {
            final String docId = DocumentUtil.getValue(doc, fessConfig.getIndexFieldId(), String.class);
            throw new FessSystemException("configId is null in document. docId: " + docId);
        }
        if (configId.length() < 2) {
            throw new FessSystemException("Invalid configId length: " + configId + ". ConfigId must be at least 2 characters long.");
        }

        } catch (final CrawlerSystemException e) {
            closeResources(httpRequest, responseData);
            throw e;
        } catch (final Exception e) {
            closeResources(httpRequest, responseData);
            throw new CrawlerSystemException("Failed to access " + url, e);
        } finally {
            EntityUtils.consumeQuietly(httpEntity);

      assertTrue(permutations.hasNext());
      permutations.next();
    }
    assertNoMorePermutations(permutations);
  }

  public void testToStringImplWithNullEntries() throws Exception {
    List<@Nullable String> list = new ArrayList<>();
    list.add("foo");
    list.add(null);

    assertThat(Collections2.toStringImpl(list)).isEqualTo(list.toString());
  }

        HashMap.class,
        Appendable.class,
        StringBuilder.class,
        StringBuffer.class,
        Throwable.class,
        Exception.class);
  }

  public void testGet_io() throws IOException {
    assertEquals(-1, ArbitraryInstances.get(InputStream.class).read());
    assertEquals(-1, ArbitraryInstances.get(ByteArrayInputStream.class).read());

   * assertions about all the public instance methods of {@link LinearTransformation}, including an
   * assertion that {@link LinearTransformation#transform} and {@link LinearTransformation#slope} on
   * its inverse throws as expected.
   */
  static void assertHorizontalLinearTransformation(LinearTransformation transformation, double y) {
    assertThat(transformation.isHorizontal()).isTrue();

            DfsReferralDataInternal result = mockReferralData.combine(null);
            assertNotNull(result);

            // Test with concrete implementation - combine with null throws NPE
            assertThrows(NullPointerException.class, () -> concreteImplementation.combine(null));
        }

        @Test
        @DisplayName("Should handle null in append")
        void testAppendWithNull() {

            @Override
            public void deleteBefore(long time) {
                throw new RuntimeException("Crawling error");
            }
        };

        SearchLogService searchLogService = new SearchLogService() {
            @Override
            public void deleteBefore(int days) {
                throw new RuntimeException("Search error");
            }
        };

    assertThat(set.size()).isAtMost(max);
  }

  /**
   * A {@link Set} that throws {@link NullPointerException} and {@link ClassCastException} from
   * {@link #contains}.
   */
  private static final class SetContainsThrows extends AbstractSet<Void> {
    @Override
    public boolean contains(@Nullable Object o) {
      throw o == null ? new NullPointerException() : new ClassCastException();
    }

    @Override

        void testToStringWithNullFileId() throws Exception {
            // Set oplockLevel but leave fileId as null
            Field oplockLevelField = Smb2OplockBreakNotification.class.getDeclaredField("oplockLevel");
            oplockLevelField.setAccessible(true);
            oplockLevelField.set(notification, (byte) 0x01);

            // The implementation calls Hexdump.toHexString which throws NPE on null