Map<String, Object> dataMap = new HashMap<>();

        // First add a single value
        transformer.putResultDataBody(dataMap, "key1", "value1");
        assertEquals("value1", dataMap.get("key1"));

        // Add an array - should merge with existing value
        String[] newValues = new String[] { "value2", "value3" };
        transformer.putResultDataBody(dataMap, "key1", newValues);

`<LifecycleConfiguration><Rule><Filter><And><Prefix>foodir/</Prefix><Tag><Key>tag1</Key><Value>value1</Value></Tag><Tag><Key>tag2</Key><Value>value2</Value></Tag></And></Filter><Status>Enabled</Status><Expiration><Date>` + time.Now().Truncate(24*time.Hour).UTC().Add(-24*time.Hour).Format(time.RFC3339) + `</Date></Expiration></Rule><Rule><Filter><And><Prefix>abc/</Prefix><Tag><Key>tag2</Key><Value>value</Value></Tag></And></Filter><Status>Enabled</Status><Expiration><Date>` + time.Now().Truncate(2...

    public void test_getFieldValues() throws Exception {
        Map<String, Object> document = new HashMap<>();
        document.put("string_field", "value1");
        document.put("string_array_field", new String[] { "value2", "value3" });
        document.put("list_field", java.util.Arrays.asList("value4", "value5"));
        document.put("int_field", 123);

        String[] stringValues = defaultContentsParser.getFieldValues(document, "string_field");

        source.put("TestKey", "value1");
        source.put("AnotherTestKey", "value2");

        Map<String, Object> nested = new HashMap<>();
        nested.put("NestedKey", "nestedValue");
        source.put("NestedMap", nested);

        Map<String, Object> result = searchLogHelper.toLowerHyphen(source);

        assertEquals("value1", result.get("test_key"));

        // Create test data
        DataConfig config = new DataConfig();
        config.setName("test-config");

        DataStoreParams params = new DataStoreParams();
        params.put("key1", "value1");
        params.put("key2", "value2");

        IndexUpdateCallback callback = new TestIndexUpdateCallback();

        // Execute store method
        dataStore.store(config, callback, params);

        // Verify store was called

        return values;
    }

    /**
     * Returns a string representation of this RequestParameter.
     * The format includes the parameter name and its values in array format.
     *
     * @return a string representation of this object in the format "[name, [value1, value2, ...]]"
     */
    @Override
    public String toString() {
        return "[" + name + ", " + Arrays.toString(values) + "]";
    }

    checkNotNull(value2);
    checkArgument(!Objects.equals(value1, value2), "Duplicate value provided.");
    distinctValues.replaceValues(type, ImmutableList.of(value1, value2));
    setDefault(type, value1);
    return this;
  }

  /**
   * Tests that {@code cls} properly checks null on all constructor and method parameters that
   * aren't annotated nullable (according to the rules of {@link NullPointerTester}). In details:
   *

        SuggestSettingsBuilder builder2 = new SuggestSettingsBuilder();

        builder1.addInitialSettings("key", "value1");
        builder2.addInitialSettings("key", "value2");

        assertEquals("value1", builder1.initialSettings.get("key"));
        assertEquals("value2", builder2.initialSettings.get("key"));
    }

    @Test
    public void testBuildMultipleInstances() {

    checkNotNull(value2);
    checkArgument(!Objects.equals(value1, value2), "Duplicate value provided.");
    distinctValues.replaceValues(type, ImmutableList.of(value1, value2));
    setDefault(type, value1);
    return this;
  }

  /**
   * Tests that {@code cls} properly checks null on all constructor and method parameters that
   * aren't annotated nullable (according to the rules of {@link NullPointerTester}). In details:
   *

        final Map<String, String[]> multiFields = Collections.singletonMap("content", new String[] { "value1", "value2" });
        assertEquals("(content:\"value1\" OR content:\"value2\")", getQuery("", new String[0], multiFields, Collections.emptyMap(), false));

        final Map<String, String[]> nullFields = Collections.singletonMap("empty", null);