public function testIsScalar()
 {
     $boolItem = new Item(true);
     $this->assertTrue($boolItem->isScalar());
     $intItem = new Item(123);
     $this->assertTrue($intItem->isScalar());
     $floatItem = new Item(1.2);
     $this->assertTrue($floatItem->isScalar());
     $stringItem = new Item('a string');
     $this->assertTrue($stringItem->isScalar());
     $arrayItem = new Item(array('an array'));
     $this->assertFalse($arrayItem->isScalar());
 }