builder.add(5L);
    ImmutableLongArray array = builder.build();
    assertThat(array.asList()).containsExactly(5L);
  }

  public void testBuilder_presize_negative() {
    assertThrows(IllegalArgumentException.class, () -> ImmutableLongArray.builder(-1));
  }

  /**
   * If there's a bug in builder growth, we wouldn't know how to expose it. So, brute force the hell