// prints countries with number of earthquakes
 // You will want to loop through the country markers or country features
 // (either will work) and then for each country, loop through
 // the quakes to count how many occurred in that country.
 // Recall that the country markers have a "name" property,
 // And LandQuakeMarkers have a "country" property set.
 private void printQuakes() {
   int totalWaterQuakes = quakeMarkers.size();
   for (Marker country : countryMarkers) {
     String countryName = country.getStringProperty("name");
     int numQuakes = 0;
     for (Marker marker : quakeMarkers) {
       EarthquakeMarker eqMarker = (EarthquakeMarker) marker;
       if (eqMarker.isOnLand()) {
         if (countryName.equals(eqMarker.getStringProperty("country"))) {
           numQuakes++;
         }
       }
     }
     if (numQuakes > 0) {
       totalWaterQuakes -= numQuakes;
       System.out.println(countryName + ": " + numQuakes);
     }
   }
   System.out.println("OCEAN QUAKES: " + totalWaterQuakes);
 }