for (Element element : document.select("a[href]")) {
        String href = element.attr("href");
        HttpUrl link = response.request().url().resolve(href);
        if (link == null) continue; // URL is either invalid or its scheme isn't http/https.
        queue.add(link.newBuilder().fragment(null).build());
      }
    }
  }

  public static void main(String[] args) throws IOException {

import com.google.common.collect.testing.features.MapFeature;
import java.util.concurrent.ConcurrentMap;
import org.junit.Ignore;

/**
 * Tester for {@link ConcurrentMap#remove}. Can't be invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.EnumMap;
import javax.annotation.CheckForNull;

/**
 * Implementation of {@link ImmutableMap} backed by a non-empty {@link java.util.EnumMap}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization

import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;

/**
 * Supplemental tests for {@link Monitor}.
 *
 * <p>This test class contains various test cases that don't fit into the test case generation in
 * {@link GeneratedMonitorTest}.
 *
 * @author Justin T. Sampson
 */
public class SupplementalMonitorTest extends TestCase {

import com.google.common.collect.Maps;
import java.util.Map;
import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * This class provides a skeletal implementation of {@link ValueGraph}. It is recommended to extend
 * this class rather than implement {@link ValueGraph} directly.
 *
 * <p>The methods implemented in this class should not be overridden unless the subclass admits a
 * more efficient implementation.
 *

import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.function.Predicate;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Collection#removeIf}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.collect.testing.features.MapFeature;
import java.util.concurrent.ConcurrentMap;
import org.junit.Ignore;

/**
 * Tester for {@link ConcurrentMap#remove}. Can't be invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import static junit.framework.Assert.fail;

import com.google.common.annotations.GwtCompatible;
import com.google.common.escape.UnicodeEscaper;

/**
 * Testing utilities for {@link UrlEscapers} and {@link LegacyUrlEscapersTest}.
 *
 * @author David Beaumont
 */
@GwtCompatible
final class UrlEscaperTesting {
  /**
   * Helper to assert common expected behaviour of uri escapers. You should call

import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;

/**
 * Supplemental tests for {@link Monitor}.
 *
 * <p>This test class contains various test cases that don't fit into the test case generation in
 * {@link GeneratedMonitorTest}.
 *
 * @author Justin T. Sampson
 */
public class SupplementalMonitorTest extends TestCase {

  static final String ENDPOINTS_MISMATCH =
      "Mismatch: endpoints' ordering is not compatible with directionality of the graph";

  /** Singleton edge value for {@link Graph} implementations backed by {@link ValueGraph}s. */
  enum Presence {
    EDGE_EXISTS
  }