/**
* Constructor
*
* @throws \InvalidArgumentException When argument is not valid.
*
* @param callable $callback Gets called for each element and gets passed the current elements
* of all iterators as arguments.
* @param array $iterators Array of iterators, which should be concurrently traversed.
*/
function __construct($callback, array $iterators)
{
if (!is_callable($callback)) {
throw new \InvalidArgumentException('Invalid callback');
}
$this->callback = $callback;
foreach ($iterators as $it) {
$this->attachIterator($it);
}
parent::__construct();
}
