class RequirementCollectionIterator

class RequirementCollectionIterator implements Iterator {
    
    /** @var Requirement[] */
    private $requirements;
    
    /** @var int */
    private $position = 0;
    public function __construct(RequirementCollection $requirements) {
        $this->requirements = $requirements->getRequirements();
    }
    public function rewind() : void {
        $this->position = 0;
    }
    public function valid() : bool {
        return $this->position < count($this->requirements);
    }
    public function key() : int {
        return $this->position;
    }
    public function current() : Requirement {
        return $this->requirements[$this->position];
    }
    public function next() : void {
        $this->position++;
    }

}