"estimated size of trySplit result (%s) is larger than original size (%s)",
                trySplit.estimateSize(), originalSize));
      }
    }
    if (subsized) {
      if (trySplit != null) {
        assertEquals(
            "sum of estimated sizes of trySplit and original spliterator after trySplit",
            originalSize,
            trySplit.estimateSize() + spliterator.estimateSize());
      } else {

            .put(2, 2)
            .put(3, 3)
            .put(4, 4)
            .put(5, 5)
            .put(6, 6)
            .buildOrThrow();
    assertNotNull(map.keySet().spliterator().trySplit());
  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(
            ImmutableMap.of(),
            ImmutableMap.builder().buildOrThrow(),