public void testLinkedHashMap() {
    @SuppressWarnings("UseCollectionConstructor") // test of factory method
    LinkedHashMap<Integer, Integer> map = Maps.newLinkedHashMap();
    assertEquals(emptyMap(), map);
  }

  public void testLinkedHashMapWithInitialMap() {
    Map<String, String> map =
        new LinkedHashMap<String, String>(
            ImmutableMap.of(
                "Hello", "World",
                "first", "second",

import javax.inject.Singleton;

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

import org.apache.maven.RepositoryUtils;

**Flow**: Poll URL → Validate → Get client → Delay → Check last-modified → Execute → Process → Extract children → Queue children → Delay

### CrawlerClientFactory

Pattern-based client selection using `LinkedHashMap<Pattern, CrawlerClient>`.

**Standard Patterns**:
```java
"^https?://.*"     → httpClient
"^file:.*"         → fileSystemClient
"^ftp://.*"        → ftpClient
"^smb://.*"        → smbClient

### 10.1 Handle Caching Strategy
```java
public class HandleCache {
    private final int maxHandles = 1000;
    private final LinkedHashMap<String, HandleInfo> lruCache;
    
    public HandleCache() {
        this.lruCache = new LinkedHashMap<String, HandleInfo>(maxHandles, 0.75f, true) {
            @Override
            protected boolean removeEldestEntry(Map.Entry<String, HandleInfo> eldest) {

import java.net.MalformedURLException;
import java.net.URL;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.maven.RepositoryUtils;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.DefaultArtifact;

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.primitives.Doubles;
import com.google.common.primitives.Ints;
import java.math.RoundingMode;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Provides a fluent API for calculating <a
 * href="http://en.wikipedia.org/wiki/Quantile">quantiles</a>.
 *
 * <h3>Examples</h3>
 *
 * <p>To compute the median:
 *

    /** Constant for the length of a unicode literal.*/
    private static final int UNICODE_LEN = 4;

    private final Map<String, String> storage = new LinkedHashMap<>();
    private final Map<String, Layout> layout = new LinkedHashMap<>();
    private List<String> header;
    private List<String> footer;
    private Path location;
    private UnaryOperator<String> callback;
    boolean substitute = true;

    /** Constant for the length of a unicode literal.*/
    private static final int UNICODE_LEN = 4;

    private final Map<String, String> storage = new LinkedHashMap<>();
    private final Map<String, Layout> layout = new LinkedHashMap<>();
    private List<String> header;
    private List<String> footer;
    private Path location;
    private UnaryOperator<String> callback;
    boolean substitute = true;

import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Arrays;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**

import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;