}
    int[] expected = {3, 1, 5, 3, 4, 5};
    checkLastIndexOf(toTest, expected);
  }

  private void checkIndexOf(List<?> toTest, int[] expected) {
    int index = 0;
    for (Object obj : toTest) {
      String name = "toTest[" + index + "] (" + obj + ")";
      assertWithMessage(name).that(Lists.indexOfImpl(toTest, obj)).isEqualTo(expected[index]);
      index++;
    }
  }

    }
    int[] expected = {3, 1, 5, 3, 4, 5};
    checkLastIndexOf(toTest, expected);
  }

  private void checkIndexOf(List<?> toTest, int[] expected) {
    int index = 0;
    for (Object obj : toTest) {
      String name = "toTest[" + index + "] (" + obj + ")";
      assertWithMessage(name).that(Lists.indexOfImpl(toTest, obj)).isEqualTo(expected[index]);
      index++;
    }
  }