The `Futures()` function violates the "functions should be named using `lowercase_with_underscores`" convention.
```
>>> Lint for src/future/functions.php:
Warning (XHP9) Naming Conventions
Follow naming conventions: functions should be named using
lowercase_with_underscores.
6 * @param list List of @{class:Future}s.
7 * @return FutureIterator New @{class:FutureIterator} over those futures.
8 */
>>> 9 function Futures($futures) {
10 return new FutureIterator($futures);
11 }
```
Maybe this should be renamed to `futures()`?