public function testSize()
{
$a = function () {
(yield 1);
(yield 2);
(yield 3);
};
$this->assertEquals(3, P::size($a()));
$this->assertEquals(3, P::size([1, 2, 3]));
$o = new StdClass();
$o->a = 1;
$o->b = 2;
$o->c = 3;
$this->assertEquals(3, P::size($o));
}