protected function setUp()
 {
     parent::setUp();
     // Since we will restrict dumping by page ranges (to allow
     // working tests, even if the db gets prepopulated by a base
     // class), we have to assert, that the page id are consecutively
     // increasing
     $this->assertEquals(array($this->pageId2, $this->pageId3, $this->pageId4), array($this->pageId1 + 1, $this->pageId2 + 1, $this->pageId3 + 1), "Page ids increasing without holes");
 }