public void test_multipleOperations() {
        // Add initial values
        dataStoreParams.put("key1", "value1");
        dataStoreParams.put("key2", 123);

        // Add more values using putAll
        Map<String, String> additionalParams = new HashMap<>();
        additionalParams.put("key3", "value3");
        additionalParams.put("key4", "value4");
        dataStoreParams.putAll(additionalParams);

        String key = "key";
        String value1 = "a";
        String value2 = "b";
        String value3 = "c";
        settings.array().add(key, value1);
        settings.array().add(key, value2);
        settings.array().add(key, value3);
        assertEquals(3, settings.array().get(key).length);
        assertEquals(value1, settings.array().get(key)[0]);
        assertEquals(value2, settings.array().get(key)[1]);

        docMap.put("key1", "value1");
        docMap.put("key2", "value2");
        docMap.put("key3", "value3");

        Collection<Object> values = docMap.values();
        assertEquals(3, values.size());
        assertTrue(values.contains("value1"));
        assertTrue(values.contains("value2"));
        assertTrue(values.contains("value3"));
    }

    @Test

      assertThat(cache.asMap().values()).containsExactly(value1, value2);
      assertThat(cache.asMap().entrySet())
          .containsExactly(immutableEntry(key1, value1), immutableEntry(key2, value2));
    }
  }

  public void testInvalidate() {
    for (LoadingCache<Key, String> cache : caches()) {
      Key key1 = new Key(1);
      String value1 = key1.toString();
      Key key2 = new Key(2);

        String expected = "[testParam, [value1, value2]]";
        assertEquals(expected, param.toString());
    }

    @Test
    public void test_toString_withNullName() {
        // Test toString with null name
        String[] values = { "value1" };
        RequestParameter param = new RequestParameter(null, values);

        String expected = "[null, [value1]]";

        // Test getting multiple different properties
        String value1 = fessConfig.get("domain.title");
        String value2 = fessConfig.get("search_engine.type");

        assertEquals("Test Fess", value1);
        assertEquals("opensearch", value2);
        assertFalse(value1.equals(value2));
    }

    // Test empty string property value
    @Test
    public void test_get_emptyStringValue() {

        String value1 = "a";
        String value2 = "b";
        String value3 = "c";
        settings.badword().add(value1);
        settings.badword().add(value2);
        settings.badword().add(value3);
        assertEquals(3, settings.badword().get(false).length);
        assertEquals(value1, settings.badword().get(false)[0]);
        assertEquals(value2, settings.badword().get(false)[1]);

    private static final String RESULT3 = COMMENT + LINE_SEPARATOR + COMMENT + LINE_SEPARATOR + KEY1A + " = " + VALUE1
            + "\\" + LINE_SEPARATOR + VALUE1 + LINE_SEPARATOR;

    @Test
    public void testSaveComment3() throws Exception {
        properties.put(KEY1, List.of(new String[] {COMMENT, COMMENT}), List.of(new String[] {VALUE1, VALUE1}));
        StringWriter sw = new StringWriter();
        properties.save(sw);

        value = "  key1  =  value1  \n  key2=value2\n";
        paramMap = ParameterUtil.parse(value);
        assertEquals(2, paramMap.size());
        assertEquals("value1", paramMap.get("key1"));
        assertEquals("value2", paramMap.get("key2"));

        // Test with empty lines and mixed whitespace
        value = "key1=value1\n\n\t\nkey2=value2\n \n";
        paramMap = ParameterUtil.parse(value);

      assertThat(cache.asMap().values()).containsExactly(value1, value2);
      assertThat(cache.asMap().entrySet())
          .containsExactly(immutableEntry(key1, value1), immutableEntry(key2, value2));
    }
  }

  public void testInvalidate() {
    for (LoadingCache<Key, String> cache : caches()) {
      Key key1 = new Key(1);
      String value1 = key1.toString();
      Key key2 = new Key(2);