Medium\Pcetr\TaskCollection.php

<?php

final class TaskCollection implements IteratorAggregate
{
    /** @var Task[] */
    private $tasks;

    /**
     * @param Task[] $tasks
     */
    public function __construct(array $tasks)
    {
        $this->tasks = $tasks;
    }

    /**
     * @param string $name
     *
     * @return Task
     */
    public function add($name)
    {
        $task = new Task($name);

        $this->tasks[] = $task;

        return $task;
    }
    
    public function getIterator() {
        foreach ($this->tasks as $task) {
            yield $task;
        }
    }
}