Collection<Integer> c = MinimalCollection.of(100);
    ImmutableList<Integer> list = ImmutableList.sortedCopyOf(c);
    assertEquals(asList(100), list);
  }

  public void testSortedCopyOf_natural_containsNull() {
    Collection<@Nullable Integer> c = MinimalCollection.of(1, 3, null, 2);
    assertThrows(
        NullPointerException.class, () -> ImmutableList.sortedCopyOf((Collection<Integer>) c));
  }

    Collection<Integer> c = MinimalCollection.of(100);
    ImmutableList<Integer> list = ImmutableList.sortedCopyOf(c);
    assertEquals(asList(100), list);
  }

  public void testSortedCopyOf_natural_containsNull() {
    Collection<@Nullable Integer> c = MinimalCollection.of(1, 3, null, 2);
    assertThrows(
        NullPointerException.class, () -> ImmutableList.sortedCopyOf((Collection<Integer>) c));
  }