anchor.diff:     });
   });
   
  +var popup = new mapboxgl.Popup({offset: 25})
  +    .setText('Construction on the Washington Monument began in 1848.');
  +
   
   </script> <!-- end of base map -->
   
  
positive.code:     layout: {
        "icon-image": "star-15",
        "icon-allow-overlap": true
  
      }
  
    })
  
    map.getSource('pins').setData({
  
negative.code:   map.addSource('pins', {
     type: 'geojson',
     data: {
       "type": "FeatureCollection",
         "features": pinFeatures
      }
    });
  