* misleading to future readers of the code and of stack traces. See <a
 * href="https://github.com/google/guava/wiki/ConditionalFailuresExplained">Conditional failures
 * explained</a> in the Guava User Guide for more advice. Notably, {@link Verify} offers assertions
 * similar to those in this class for non-precondition checks.
 *
 * <h3>{@code java.util.Objects.requireNonNull()}</h3>
 *

 * misleading to future readers of the code and of stack traces. See <a
 * href="https://github.com/google/guava/wiki/ConditionalFailuresExplained">Conditional failures
 * explained</a> in the Guava User Guide for more advice. Notably, {@link Verify} offers assertions
 * similar to those in this class for non-precondition checks.
 *
 * <h3>{@code java.util.Objects.requireNonNull()}</h3>
 *

 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman

 *
 * <pre>
 *   String trimmed = {@link #whitespace() whitespace()}.{@link #trimFrom trimFrom}(userInput);
 *   if ({@link #ascii() ascii()}.{@link #matchesAllOf matchesAllOf}(s)) { ... }</pre>
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/StringsExplained#charmatcher">{@code CharMatcher}
 * </a>.
 *
 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible(emulated = true)

	PKCS1WithSHA1 SignatureScheme = 0x0201
	ECDSAWithSHA1 SignatureScheme = 0x0203
)

// ClientHelloInfo contains information from a ClientHello message in order to
// guide application logic in the GetCertificate and GetConfigForClient callbacks.
type ClientHelloInfo struct {
	// CipherSuites lists the CipherSuites supported by the client (e.g.

 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman

 * are <i>lazy</i>, which means that they only advance the backing iteration when absolutely
 * necessary.
 *
 * <p>See the Guava User Guide section on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#iterables">{@code
 * Iterators}</a>.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @since 2.0
 */

 *
 * <pre>
 *   String trimmed = {@link #whitespace() whitespace()}.{@link #trimFrom trimFrom}(userInput);
 *   if ({@link #ascii() ascii()}.{@link #matchesAllOf matchesAllOf}(s)) { ... }</pre>
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/StringsExplained#charmatcher">{@code CharMatcher}
 * </a>.
 *
 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible(emulated = true)

 * are <i>lazy</i>, which means that they only advance the backing iteration when absolutely
 * necessary.
 *
 * <p>See the Guava User Guide section on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#iterables">{@code
 * Iterators}</a>.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @since 2.0
 */

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Static utility methods pertaining to the {@link Future} interface.
 *
 * <p>Many of these methods use the {@link ListenableFuture} API; consult the Guava User Guide
 * article on <a href="https://github.com/google/guava/wiki/ListenableFutureExplained">{@code
 * ListenableFuture}</a>.
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of