public function testGetPrevious()
{
$col = new Collection();
$this->assertNull($col->getPrevious(), 'getPrevious() returns null on an empty collection');
$data = array('bar1', 'bar2', 'bar3');
$col = new Collection($data);
$this->assertNull($col->getPrevious(), 'getPrevious() returns null when the internal pointer is at the beginning of the list');
$col->getNext();
$this->assertEquals('bar1', $col->getPrevious(), 'getPrevious() returns the previous element');
$this->assertEquals('bar1', $col->getCurrent(), 'getPrevious() decrements the internal pointer');
}
