public static final NullsBeforeTwo INSTANCE = new NullsBeforeTwo();

    private NullsBeforeTwo() {
      super("two"); // from TestStringSortedMapGenerator's sample keys
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getMethod(Class<?> clazz, String name) {
    try {
      return clazz.getMethod(name);

  @GwtIncompatible // java.nio.charset.Charset

  public void testIsWellFormed_3Bytes() {
    testBytes(3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
  }

  /**
   * Tests that round tripping of a sample of four byte permutations work. All permutations are
   * prohibitively expensive to test for automated runs. This method tests specific four-byte cases.
   */
  public void testIsWellFormed_4BytesSamples() {

      // derive values for inclusive filtering from the input samples
      SampleElements<Entry<K, V>> samples = delegate.samples();
      List<Entry<K, V>> samplesList =
          Arrays.asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());
      Collections.sort(samplesList, entryComparator);
      this.firstInclusive = samplesList.get(0).getKey();

    }
  }

  /**
   * Returns the <a href="http://en.wikipedia.org/wiki/Arithmetic_mean">arithmetic mean</a> of
   * {@code values}.
   *
   * <p>If these values are a sample drawn from a population, this is also an unbiased estimator of
   * the arithmetic mean of the population.
   *
   * @param values a nonempty series of values

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates collections, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestCollectionGenerator<E extends @Nullable Object>

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import java.util.Queue;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates queues, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestQueueGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates sets, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestListGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {

  SortedMap<K, V> create(Object... elements);

  /**
   * Returns an entry with a key less than the keys of the {@link #samples()} and less than the key
   * of {@link #belowSamplesGreater()}.
   */
  Entry<K, V> belowSamplesLesser();

  /**
   * Returns an entry with a key less than the keys of the {@link #samples()} but greater than the
   * key of {@link #belowSamplesLesser()}.
   */
  Entry<K, V> belowSamplesGreater();

  /**

import com.google.common.collect.testing.TestContainerGenerator;
import java.util.Collection;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates multimaps, containing sample elements, to be tested.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestMultimapGenerator<

 * <strong>Performance</strong>).
 *
 * <p><strong>Cycle Detection</strong>
 *
 * <p>Deadlocks can arise when locks are acquired in an order that forms a cycle. In a simple
 * example involving two locks and two threads, deadlock occurs when one thread acquires Lock A, and
 * then Lock B, while another thread acquires Lock B, and then Lock A:
 *
 * <pre>
 * Thread1: acquire(LockA) --X acquire(LockB)