} catch (ConfigPropertyNotFoundException e) {
            // Expected exception
            assertTrue(e.getMessage().contains("filter.null"));
        }
    }

    // Test concurrent access
    @Test
    public void test_get_concurrentAccess() throws InterruptedException {
        // Create multiple threads accessing the same property
        final String testKey = "domain.title";

            <option value="$PROJECT_DIR$/platforms/core-runtime/client-services" />
            <option value="$PROJECT_DIR$/platforms/core-runtime/collections" />
            <option value="$PROJECT_DIR$/platforms/core-runtime/concurrent" />
            <option value="$PROJECT_DIR$/platforms/core-runtime/daemon-logging" />
            <option value="$PROJECT_DIR$/platforms/core-runtime/daemon-main" />

import java.nio.file.Path;
import java.util.List;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.concurrent.CommonPoolUtil;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.fess.Constants;
import org.codelibs.fess.app.pager.ElevateWordPager;
import org.codelibs.fess.app.service.ElevateWordService;

        CharMappingItem item = result.get(0);
        assertArrayEquals(new String[] { "x", "y" }, item.getInputs());
        assertEquals("z", item.getOutput());
    }

    // Test concurrent modification
    @Test
    public void test_concurrentModification() throws Exception {
        writeTestFile("a,b => c\nd,e => f\n");

        // Get an item

import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.CoreLibConstants;

            } else {
                System.clearProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);
            }
        }
    }

    @Test
    public void test_thread_safety() {
        // Test concurrent access to the method
        String originalValue = System.getProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);

        try {
            System.setProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS, "thread-test");

import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;

import org.codelibs.curl.CurlRequest;
import org.codelibs.curl.CurlResponse;
import org.codelibs.curl.io.ContentCache;

import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.function.Consumer;
import java.util.stream.Collectors;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.apache.logging.log4j.LogManager;

 */
package org.codelibs.fess.helper;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.BiConsumer;
import java.util.stream.Collectors;

import org.codelibs.fess.app.service.WebConfigService;
import org.codelibs.fess.mylasta.direction.FessConfig;

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.llm;

import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.Constants;
import org.codelibs.fess.util.ComponentUtil;

/**