// Should not throw exception
    }

    // Test addFieldLog with existing field
    public void test_addFieldLog_existingField() {
        Map<String, List<String>> fieldLogMap = new HashMap<>();
        List<String> existingList = new ArrayList<>();
        existingList.add("existing");
        fieldLogMap.put("field", existingList);

        Map<String, Object> dataMap = new HashMap<>();
        dataMap.put("url", "http://example.com/test");
        dataMap.put("doc_id", "existing-doc-id");

        indexUpdateCallback.store(paramMap, dataMap);

        // Should keep existing doc_id
        assertEquals("existing-doc-id", dataMap.get("doc_id"));
    }

    public void test_concurrentStore() throws Exception {
        // Test thread safety

    public void test_update() throws Exception {
        writeTestFile("a,b => c\nd,e => f\n");

        // Get existing item
        OptionalEntity<CharMappingItem> existing = charMappingFile.get(1L);
        assertTrue(existing.isPresent());

        // Update the item
        CharMappingItem updateItem = existing.get();
        updateItem.setNewInputs(new String[] { "m", "n" });
        updateItem.setNewOutput("o");

        assertNotNull(filename);
        assertTrue(filename.endsWith(".jpg"));
        assertTrue(filename.contains(docid));
    }

    // Test getThumbnailFile with existing file
    public void test_getThumbnailFile_exists() throws IOException {
        Map<String, Object> docMap = new HashMap<>();
        docMap.put("_id", "testdoc");

      } // else no check necessary, all index values are valid
      L existing = locks.get(index);
      if (existing != null) {
        return existing;
      }
      L created = supplier.get();
      existing = locks.putIfAbsent(index, created);
      return MoreObjects.firstNonNull(existing, created);
    }

    @Override
    public int size() {
      return size;
    }
  }

        // Write an existing item (should pass through)
        ProtwordsItem existingItem = new ProtwordsItem(10, "existing");
        ProtwordsItem result = updater.write(existingItem);

        assertNotNull(result);
        assertEquals("existing", result.getInput());
        assertEquals(10, result.getId());

        updater.close();
    }

                form.initialize();
                form.crudMode = CrudMode.CREATE;
                form.dictId = dictId;
            });
        });
    }

    /**
     * Display the edit form for an existing stopwords entry.
     *
     * @param form the edit form containing the entry ID and dictionary ID
     * @return HTML response for the edit form
     */
    @Execute
    @Secured({ ROLE })

      } else {
        // We already saw this key, and the first value we saw (going backwards) is the one we are
        // keeping. So we won't touch table[], but we do still want to add the existing entry that
        // we found to entries[] so that we will see this key in the right place when iterating.
        if (duplicates == null) {
          duplicates = new IdentityHashMap<>();
        }

        } catch (IllegalArgumentException e) {
            assertEquals("name or dataStore is null.", e.getMessage());
        }
    }

    // Test getDataStore with existing name
    public void test_getDataStore_existingName() {
        TestDataStore dataStore = new TestDataStore("TestStore");
        dataStoreFactory.add("myStore", dataStore);

    EnumHashBiMap<Currency, Country> bimap2 = EnumHashBiMap.create(emptyBimap2);
    assertTrue(bimap2.isEmpty());
  }

  public void testEnumHashBiMapConstructor() {
    /* Test that it copies existing entries. */
    EnumHashBiMap<Currency, String> bimap1 = EnumHashBiMap.create(Currency.class);
    bimap1.put(Currency.DOLLAR, "dollar");
    EnumHashBiMap<Currency, String> bimap2 = EnumHashBiMap.create(bimap1);