public function testShouldUnshiftValue()
{
$value = 'value';
$value2 = 'value2';
$valueToUnshift = 'valueToUnshift';
$this->list->add($value);
$this->assertEquals($value, $this->list->first());
$this->list->add($value2);
$this->assertEquals($value, $this->list->first());
$this->list->unshift($valueToUnshift);
$this->assertEquals($valueToUnshift, $this->list->first());
}
