## Conversão automática { #automatic-conversion }

`Header` tem algumas funcionalidades a mais em relação a `Path`, `Query` e `Cookie`.

A maioria dos cabeçalhos padrão são separados pelo caractere "hífen", também conhecido como "sinal de menos" (`-`).

Mas uma variável como `user-agent` é inválida em Python.

  public Set<Entry<E>> entrySet() {
    Set<Entry<E>> result = entrySet;
    return (result == null) ? entrySet = createEntrySet() : result;
  }

  Set<Entry<E>> createEntrySet() {
    @WeakOuter
    final class EntrySetImpl extends Multisets.EntrySet<E> {
      @Override
      Multiset<E> multiset() {
        return DescendingMultiset.this;
      }

      @Override
      public Iterator<Entry<E>> iterator() {

import com.google.common.annotations.GwtCompatible;
import org.jspecify.annotations.Nullable;

/** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
@GwtCompatible
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *

 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class ForwardingSortedMultisetTest extends TestCase {
  static class StandardImplForwardingSortedMultiset<E> extends ForwardingSortedMultiset<E> {
    private final SortedMultiset<E> backingMultiset;

    StandardImplForwardingSortedMultiset(SortedMultiset<E> backingMultiset) {
      this.backingMultiset = backingMultiset;
    }

    @Override

import com.google.common.annotations.GwtCompatible;
import org.jspecify.annotations.Nullable;

/** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
@GwtCompatible
final class NullnessCasts {
  /**
   * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that
   * that conversion is safe.
   *

  abstract X toX(double d, RoundingMode mode);

  /** Returns a - b, guaranteed that both arguments are nonnegative. */
  abstract X minus(X a, X b);

  /** Rounds {@code x} to a {@code double}. */
  final double roundToDouble(X x, RoundingMode mode) {
    checkNotNull(x, "x");
    checkNotNull(mode, "mode");
    double roundArbitrarily = roundToDoubleArbitrarily(x);
    if (Double.isInfinite(roundArbitrarily)) {

  @GwtIncompatible // NullPointerTester
  public void testNullPointerExceptions() {
    new NullPointerTester().testAllPublicStaticMethods(Maps.class);
  }

  private static final Map<Integer, Integer> EMPTY = emptyMap();
  private static final Map<Integer, Integer> SINGLETON = singletonMap(1, 2);

  public void testMapDifferenceEmptyEmpty() {
    MapDifference<Integer, Integer> diff = Maps.difference(EMPTY, EMPTY);

 * when there is a specific reason to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashSet<E extends @Nullable Object> extends CompactHashSet<E> {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {

 * when there is a specific reason to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashSet<E extends @Nullable Object> extends CompactHashSet<E> {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {

/**
 * Tests {@link SequentialExecutor}.
 *
 * @author JJ Furman
 */
@NullUnmarked
public class SequentialExecutorTest extends TestCase {

  private static class FakeExecutor implements Executor {
    final Queue<Runnable> tasks = new ArrayDeque<>();

    @Override
    public void execute(Runnable command) {
      tasks.add(command);
    }

    boolean hasNext() {
      return !tasks.isEmpty();
    }