function testHideForId()
 {
     $mb = new CMB_Meta_Box(array('title' => 'Test Meta Box', 'pages' => 'post', 'fields' => array(array('id' => 'test', 'name' => 'Test', 'type' => 'text')), 'hide_on' => array('id' => 2)));
     // Test is shown when no ID is set.
     $displayed = $mb->hide_for_id(true);
     $this->assertTrue($displayed);
     // Test hidden for post ID
     $_GET['post'] = 2;
     $displayed = $mb->hide_for_id(true);
     $this->assertFalse($displayed);
     // Test not hidden when post ID doesn't match.
     $_GET['post'] = 3;
     $displayed = $mb->hide_for_id(true);
     $this->assertTrue($displayed);
     unset($_GET['post']);
 }