debugGoCollectorPath: collectors.NewGoCollector(),
	}

	// Add all `MetricGroup` collectors to the map.
	for _, mg := range allMetricGroups {
		collectors[mg.CollectorPath] = mg
	}

	// Helper function to register a collector and return a gatherer for it.
	mustRegister := func(c ...prometheus.Collector) prometheus.Gatherer {
		subRegistry := prometheus.NewRegistry()
		for _, col := range c {

        assertEquals(3, result.size());
        assertEquals("first", result.get(0));
        assertNull(result.get(1));
        assertEquals("third", result.get(2));
    }

    /**
     * Test helper class for serialization tests
     */
    public static class TestSerializableClass implements Serializable {
        private static final long serialVersionUID = 1L;

        public String name;

        SingletonContext.registerSmbURLHandler();
        assertEquals("com.example|jcifs|org.test", System.getProperty("java.protocol.handler.pkgs"));
    }

    // Helper method to get the singleton instance via reflection for assertion
    private Object getSingletonInstanceViaReflection() {
        try {
            Field instance = SingletonContext.class.getDeclaredField("INSTANCE");

## Vorbehalt { #caveat }

import org.codelibs.fess.app.pager.DuplicateHostPager;
import org.codelibs.fess.app.service.DuplicateHostService;
import org.codelibs.fess.app.web.CrudMode;
import org.codelibs.fess.app.web.base.FessAdminAction;
import org.codelibs.fess.helper.SystemHelper;
import org.codelibs.fess.opensearch.config.exentity.DuplicateHost;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;

        return _preference;
    }

    // ===================================================================================
    //                                                                      General Helper
    //                                                                      ==============
    protected String ln() {
        return DBFluteSystem.ln();
    }

import org.codelibs.fess.crawler.exception.ExtractException;
import org.codelibs.fess.crawler.extractor.Extractor;
import org.codelibs.fess.crawler.extractor.ExtractorFactory;
import org.codelibs.fess.crawler.helper.MimeTypeHelper;

import jakarta.mail.Address;
import jakarta.mail.BodyPart;
import jakarta.mail.Header;
import jakarta.mail.Message;
import jakarta.mail.MessagingException;
import jakarta.mail.Multipart;

        return _preference;
    }

    // ===================================================================================
    //                                                                      General Helper
    //                                                                      ==============
    protected String ln() {
        return DBFluteSystem.ln();
    }

        // Create URL with registered handler
        URL smbUrl = new URL("smb://server/share/dir/");
        lenient().when(locator.getURL()).thenReturn(smbUrl);
    }

    // Helper: reflectively set private/protected field on an object
    private static void setField(Object target, Class<?> declaring, String name, Object value) {
        try {
            Field f = declaring.getDeclaredField(name);

    return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {
    assertEquals(expected, map);
    assertEquals(expected.hashCode(), map.hashCode());