Oinktube/vendor/stripe/stripe-php/lib/Util/Set.php

<?php

namespace Stripe\Util;

class Set implements \IteratorAggregate
{
    private $_elts;

    public function __construct($members = [])
    {
        $this->_elts = [];
        foreach ($members as $item) {
            $this->_elts[$item] = true;
        }
    }

    public function includes($elt)
    {
        return isset($this->_elts[$elt]);
    }

    public function add($elt)
    {
        $this->_elts[$elt] = true;
    }

    public function discard($elt)
    {
        unset($this->_elts[$elt]);
    }

    public function toArray()
    {
        return \array_keys($this->_elts);
    }

    /**
     * @return \ArrayIterator
     */
    #[\ReturnTypeWillChange]
    public function getIterator()
    {
        return new \ArrayIterator($this->toArray());
    }
}