assertThat(graph.edgeValue(2, 1).orElse(DEFAULT)).isEqualTo(DEFAULT);
    assertThat(graph.edgeValueOrDefault(1, 2, null)).isNull();
    assertThat(graph.edgeValueOrDefault(2, 1, null)).isNull();
    assertThat(graph.edgeValue(1, 2).orElse(null)).isNull();
    assertThat(graph.edgeValue(2, 1).orElse(null)).isNull();

    graph.putEdgeValue(1, 2, "valueA");
    graph.putEdgeValue(2, 1, "valueB");

  }

  /*
   * Tests for Predicates.isNull()
   */

  public void testIsNull_apply() {
    Predicate<@Nullable Integer> isNull = Predicates.isNull();
    assertTrue(isNull.apply(null));
    assertFalse(isNull.apply(1));
  }

  public void testIsNull_equality() {
    new EqualsTester()
        .addEqualityGroup(Predicates.isNull(), Predicates.isNull())
        .addEqualityGroup(Predicates.notNull())

    assertFalse(equalTo1.apply(null));
    Predicate<@Nullable Object> isNull = Equivalence.equals().equivalentTo(null);
    assertFalse(isNull.apply("1"));
    assertFalse(isNull.apply("2"));
    assertTrue(isNull.apply(null));

    new EqualsTester()
        .addEqualityGroup(equalTo1, Equivalence.equals().equivalentTo("1"))
        .addEqualityGroup(isNull)
        .addEqualityGroup(Equivalence.identity().equivalentTo("1"))

   */
  private static final SuccessorsFunction<Character> TWO_TREES = createDirectedGraph("ab", "cd");

  /**
   * A graph consisting of a single root {@code a}:
   *
   * <pre>{@code
   * a
   * }</pre>
   */
  private static final SuccessorsFunction<Character> SINGLE_ROOT = createSingleRootGraph();

  /**
   * A graph that is not a tree (for example, it has two antiparallel edge between {@code e} and

    return suite;
  }

  public void testAllocArraysDefault() {
    CompactHashSet<Integer> set = CompactHashSet.create();
    assertThat(set.needsAllocArrays()).isTrue();
    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {

    return suite;
  }

  public void testAllocArraysDefault() {
    CompactHashSet<Integer> set = CompactHashSet.create();
    assertThat(set.needsAllocArrays()).isTrue();
    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {

  /**
   * Given a collection of exceptions, returns a {@link RuntimeException}, with the following rules:
   *
   * <ul>
   *   <li>If {@code exceptions} has a single exception and that exception is a {@link
   *       RuntimeException}, return it
   *   <li>If {@code exceptions} has a single exceptions and that exceptions is not a
   *       {@link RuntimeException}, return a simple {@code RuntimeException} that wraps it

    }

    // wait for entries to expire, but don't call expireEntries
    ticker.advance(EXPIRING_TIME * 10, MILLISECONDS);

    // add a single unexpired entry
    cache.getUnchecked(KEY_PREFIX + 11);

    // collections views shouldn't expose expired entries
    assertEquals(1, Iterators.size(cache.asMap().entrySet().iterator()));

import java.util.Collection;
import java.util.Map;

/**
 * Enumerates several algorithms providing equivalent functionality to {@link Quantiles}, for use in
 * {@link QuantilesBenchmark}. These algorithms each calculate either a single quantile or multiple
 * quantiles. All algorithms modify the dataset they are given (the cost of a copy to avoid this
 * will be constant across algorithms).
 *
 * @author Pete Gillin
 * @since 20.0
 */

import java.util.Collection;
import java.util.Map;

/**
 * Enumerates several algorithms providing equivalent functionality to {@link Quantiles}, for use in
 * {@link QuantilesBenchmark}. These algorithms each calculate either a single quantile or multiple
 * quantiles. All algorithms modify the dataset they are given (the cost of a copy to avoid this
 * will be constant across algorithms).
 *
 * @author Pete Gillin
 * @since 20.0
 */