public function testUnnest()
{
$a = function () {
(yield 1);
(yield [2]);
(yield [[3]]);
};
$a = [1, 2, [[3]]];
$this->assertEquals([1, 2, [3]], P::toArray(P::unnest($a)));
$b = [[1, 2], [3, 4], [5, 6]];
$this->assertEquals([1, 2, 3, 4, 5, 6], P::toArray(P::unnest($b)));
}
