Collections\Collection::dropRight PHP Method

    public function dropRight($num)
    {
        return $num != $this->count() ? $this->slice(0, $this->count() - $num - 1) : $this->clear();
    }

 public function test_dr_all_but_one_leaves_first_item()
 {
     $col = $this->col->dropRight(2);
     $this->assertEquals(1, $col->count());
     $this->assertEquals($this->items[0], $col->at(0));
 }