Sets.newSetFromMap(map);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  /** The 0-ary cartesian product is a single empty list. */
  public void testCartesianProduct_zeroary() {
    assertThat(Sets.cartesianProduct()).containsExactly(list());
  }

  /** A unary cartesian product is one list of size 1 for each element in the input set. */
  public void testCartesianProduct_unary() {

    return multimap.asMap();
  }

  /**
   * Returns a multimap view of the specified map. The multimap is backed by the map, so changes to
   * the map are reflected in the multimap, and vice versa. If the map is modified while an
   * iteration over one of the multimap's collection views is in progress (except through the
   * iterator's own {@code remove} operation, or through the {@code setValue} operation on a map

        for (int i = count; i < size; i++) {
          array[i] = null; // for GWT
        }

        List<@Nullable T> list = Collections.unmodifiableList(Arrays.asList(array));
        // TODO(b/192579700): Use a ternary once it no longer confuses our nullness checker.
        if (pad || count == size) {
          return list;
        } else {
          return list.subList(0, count);
        }
      }
    };
  }