public function testDifferenceWithArrays()
{
$A = new Set([1, 2, [1, 2, 3]]);
$B = new Set([2, 3, [2, 3, 4]]);
$A∖B = $A->difference($B);
$expected = new Set([1, [1, 2, 3]]);
$this->assertEquals($expected, $A∖B);
$this->assertEquals($expected->asArray(), $A∖B->asArray());
$A = new Set([1, 2, [1, 2, 3]]);
$B = new Set([2, 3, [2, 3, 4], [1, 2, 3]]);
$A∖B = $A->difference($B);
$expected = new Set([1]);
$this->assertEquals($expected, $A∖B);
$this->assertEquals($expected->asArray(), $A∖B->asArray());
}