public function testOffsetSet()
{
$n = new Node();
self::$n->offsetSet(1, $n);
$this->assertEquals($n, self::$n[1]);
$n1 = new Node();
self::$n->offsetSet(100, $n1);
$this->assertEquals($n1, self::$n->last());
$n2 = new Node();
self::$n->offsetSet(0, $n2);
$this->assertEquals($n2, self::$n->first());
foreach (self::$n as $key => $child) {
$keys[] = $key;
$nodes[] = $child;
}
$this->assertEquals([$n2, $n, self::$n2, $n1], $nodes);
$this->assertEquals([0, 1, 2, 3], $keys);
}
