Checking if `$callback` is callable, but then calling `$this->callback()`

[nathanbrauer]

Regarding this portion....

silverstripe-salsify/src/Traits/Yieldable.php

Lines 36 to 38 in 6068d6c

	if (is_callable($callback)) {
	$this->callback();
	}

...of this method...

silverstripe-salsify/src/Traits/Yieldable.php

Lines 17 to 39 in 6068d6c

	/**
	* @param array|iterable $list
	* @param callable|null $callback
	* @return \Generator
	*/
	public function yieldSingle($list, $callback = null)
	{
	if (!is_array($list) && !$list instanceof \Traversable) {
	$list = [$list];
	}
	foreach ($list as $item) {
	$injected = (yield $item);
	if ($injected === static::$STOP_GENERATOR) {
	break;
	}
	}
	if (is_callable($callback)) {
	$this->callback();
	}
	}

We check to see if $callback is callable, but then we call $this->callback() instead of $callback().

Is this intentional? If so, shouldn't $callback just be boolean?