// no entry
    assertEquals(0, segment.count);
    assertNull(segment.remove(key, hash));
    assertEquals(0, segment.count);

    // same key
    table.set(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    assertSame(oldValue, segment.remove(key, hash));
    assertEquals(0, segment.count);
    assertNull(segment.get(key, hash));

    // no entry
    assertEquals(0, segment.count);
    assertNull(segment.remove(key, hash));
    assertEquals(0, segment.count);

    // same key
    table.set(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    assertSame(oldValue, segment.remove(key, hash));
    assertEquals(0, segment.count);
    assertNull(segment.get(key, hash));

      assertEquals("Segments must be empty by now", 0, segmentSize(segment));
    }
    cchm.processPendingNotifications();
  }

  static void expireEntries(Segment<?, ?> segment, long now) {
    segment.lock();
    try {
      segment.expireEntries(now);
      segment.cleanUp();
    } finally {
      segment.unlock();
    }
  }

    assertSame(oldValue, segment.remove(key, hash));
    assertEquals(0, segment.count);
    assertNull(segment.get(key, hash));

    // cleared
    segment.setTableEntryForTesting(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    oldValueRef.clear();
    assertNull(segment.remove(key, hash));
    assertEquals(0, segment.count);

    assertSame(oldValue, segment.remove(key, hash));
    assertEquals(0, segment.count);
    assertNull(segment.get(key, hash));

    // cleared
    segment.setTableEntryForTesting(index, entry);
    segment.count++;
    assertEquals(1, segment.count);
    assertSame(oldValue, segment.get(key, hash));
    oldValueRef.clear();
    assertNull(segment.remove(key, hash));
    assertEquals(0, segment.count);

     */
    long sum = 0L;
    Segment<K, V, E, S>[] segments = this.segments;
    for (int i = 0; i < segments.length; ++i) {
      if (segments[i].count != 0) {
        return false;
      }
      sum += segments[i].modCount;
    }

    if (sum != 0L) { // recheck unless no modifications
      for (int i = 0; i < segments.length; ++i) {
        if (segments[i].count != 0) {
          return false;

      for (Segment<K, V> segment : segments) {
        if (segment.count != 0) {
          return false;
        }
        sum -= segment.modCount;
      }
      return sum == 0L;
    }
    return true;
  }

  long longSize() {
    Segment<K, V>[] segments = this.segments;
    long sum = 0;
    for (Segment<K, V> segment : segments) {
      sum += segment.count;
    }

      for (Segment<K, V> segment : segments) {
        if (segment.count != 0) {
          return false;
        }
        sum -= segment.modCount;
      }
      return sum == 0L;
    }
    return true;
  }

  long longSize() {
    Segment<K, V>[] segments = this.segments;
    long sum = 0;
    for (Segment<K, V> segment : segments) {

      assertEquals("Segments must be empty by now", 0, segmentSize(segment));
    }
    cchm.processPendingNotifications();
  }

  static void expireEntries(Segment<?, ?> segment, long now) {
    segment.lock();
    try {
      segment.expireEntries(now);
      segment.cleanUp();
    } finally {
      segment.unlock();
    }
  }

import com.google.common.cache.LocalCache.Segment;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Benchmark for {@code LocalCache.Segment.removeEntryFromChain}.
 *
 * @author Charles Fry
 */
@SuppressWarnings("CheckReturnValue")
public class ChainBenchmark {

  @Param({"1", "2", "3", "4", "5", "6"})
  int length;

  private Segment<Object, Object> segment;
  private ReferenceEntry<Object, Object> head;