import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * A wrapper implementation of Map<String, Object> that provides special handling
 * for document data. This class wraps an existing map and provides custom behavior
 * for the entrySet method to ensure language fields appear first in iteration order.
 * Used throughout the Fess search system for document data manipulation.
 *
 */

    install|upgrade)

        # Create fess group if not existing
        if ! getent group "$FESS_GROUP" > /dev/null 2>&1 ; then
            echo -n "Creating $FESS_GROUP group..."
            addgroup --quiet --system "$FESS_GROUP"
            echo " OK"
        fi

        # Create fess user if not existing
        if ! id $FESS_USER > /dev/null 2>&1 ; then

### New properties in an existing class

When adding a property to an existing class (task, extension, domain object, etc), the API should consist of managed lazy properties.  However, some exceptions need to be made to keep backwards compatibility with existing builds.

This is preferred when the implementation type is internal:

```groovy

        params = new ParamMap<>(new HashMap<>());
    }

    /**
     * Creates a new DataStoreParams instance with a copy of the provided parameters.
     * This protected constructor is used for creating new instances from existing parameter maps.
     *
     * @param params the parameter map to copy, must not be null
     */
    protected DataStoreParams(final Map<String, Object> params) {

        // Should not throw exception
    }

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

    }

    def "can clean existing API changes"() {
        given:
        jsonFile << existingAcceptedApiChanges()

        when:
        jsonFileManager.emptyAcceptedApiChanges(jsonFile)

        then:
        jsonFile.text == nonExistentAcceptedApiChanges()
    }

    def "can clean non-existing API changes"() {
        given:

        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"));
    }

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

### Negative Consequences

* **Historical inconsistencies**: Existing code may contain British English spellings that cannot be changed due to backward compatibility

### Migration and Enforcement

* **New code**: All new contributions must use American English

    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");

        // Test loading into existing map
        paramMap = new HashMap<>();
        paramMap.put("existing", "existingValue");
        configParam = "key1=value1\nkey2=value2";
        ParameterUtil.loadConfigParams(paramMap, configParam);
        assertEquals(3, paramMap.size());
        assertEquals("existingValue", paramMap.get("existing"));
        assertEquals("value1", paramMap.get("key1"));