// same key
    segment.setTableEntryForTesting(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));

    // cleared
    segment.setTableEntryForTesting(index, entry);
    segment.count++;

    // same key
    segment.setTableEntryForTesting(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));

    // cleared
    segment.setTableEntryForTesting(index, entry);
    segment.count++;

      throw new AssertionError();
    }

    /**
     * Unsafely sets the given index of this segment's internal hash table to be the given entry.
     */
    void setTableEntryForTesting(int i, InternalEntry<K, V, ?> entry) {
      table.set(i, castForTesting(entry));
    }

    /** Unsafely returns a copy of the given entry. */