Escaper escaper = Escapers.nullEscaper();
    EscaperAsserts.assertBasic(escaper);
    String s = "\0\n\t\\az09~\uD800\uDC00\uFFFF";
    assertWithMessage("null escaper should have no effect").that(escaper.escape(s)).isEqualTo(s);
  }

  public void testBuilderInitialStateNoReplacement() {
    // Unsafe characters aren't modified by default (unsafeReplacement == null).

 * @param <V> The value type of the map implementation under test.
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapEntrySetTester<K, V> extends AbstractMapTester<K, V> {
  private enum IncomparableType {

 * @param <V> The value type of the map implementation under test.
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapEntrySetTester<K, V> extends AbstractMapTester<K, V> {
  private enum IncomparableType {

 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
@SuppressWarnings({
  // @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
  "JUnit4ClassUsedInJUnit3",
  // We use ::iterator so that we test passing a plain Iterable, not a Collection.
  "UnnecessaryMethodReference",
})

  private fun handleSocketEffect(
    effect: SocketEffect?,
    socket: MockWebServerSocket,
    stream: Http2Stream? = null,
  ): Boolean {
    if (effect == null) return false

    when (effect) {
      is CloseStream -> {
        if (stream != null) {
          stream.close(ErrorCode.fromHttp2(effect.http2ErrorCode)!!, null)
        } else {
          socket.close()
        }

 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class CollectionRetainAllTester<E> extends AbstractCollectionTester<E> {

 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapCreationTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(ALLOWS_NULL_KEYS)

import org.junit.Ignore;

/** Tester for {@code BiMap.put} and {@code BiMap.forcePut}. */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class BiMapPutTester<K, V> extends AbstractBiMapTester<K, V> {

  @MapFeature.Require(SUPPORTS_PUT)

 *
 * @author George van den Driessche
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class CollectionRemoveTester<E> extends AbstractCollectionTester<E> {

/**
 * Tester for {@code Multimap.entries}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultimapEntriesTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {