public function test_max_page()
 {
     $mp = PagerCalculator::calculate_maxpage(17, 18);
     $this->assertEquals(0, $mp);
     $mp = PagerCalculator::calculate_maxpage(18, 18);
     $this->assertEquals(0, $mp);
     $mp = PagerCalculator::calculate_maxpage(19, 18);
     $this->assertEquals(1, $mp);
 }