public function testGetPrevUrl()
 {
     $this->paginator->setCurrentPage(2);
     $this->paginator->setUrlPattern('/example/page(:num)');
     $this->assertEquals('/example/page1', $this->paginator->getPrevUrl());
     // Returns null if on the first page.
     $this->paginator->setCurrentPage(1);
     $this->assertNull($this->paginator->getPrevUrl());
 }