public function testRemove()
{
$elements = [1, 'A' => 'a', 2, 'B' => 'b', 3];
$collection = new ArrayCollection($elements);
$this->assertSame(1, $collection->remove(0));
unset($elements[0]);
$this->assertSame(null, $collection->remove('non-existent'));
unset($elements['non-existent']);
$this->assertSame(2, $collection->remove(1));
unset($elements[1]);
$this->assertSame('a', $collection->remove('A'));
unset($elements['A']);
$this->assertSame($elements, $collection->toArray());
}
