public function testConstructAndGetAndSet()
 {
     $array = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
     $ah = new ArrayHelper($array);
     // Make sure we are not using by reference
     $this->assertEquals(10, $ah->pop());
     $this->assertEquals(10, $ah->pop());
     // Make sure we are not using by reference
     $this->assertEquals(1, $ah->shift());
     $this->assertEquals(1, $ah->shift());
     $ah->setMutable(true);
     $this->assertEquals(1, $ah->shift());
     $this->assertEquals(2, $ah->shift());
     $ah->unshift(2, 1);
     $this->assertEquals(1, $ah->shift());
 }