title: setMap is not working
body: <p>Feel that understood a lot, but stuck again on new item..<br>
  I'm trying to delete marker from the map created with <strong>Google Map API</strong>.<br>
  I have a Delete marker button inside the infoWindow.</p>
  
  <p><a href="https://i.stack.imgur.com/8f5wq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8f5wq.jpg" alt="enter image description here"></a></p>
  
  <p>There is my code below:</p>
  
  <pre><code>function DeleteMarker(index) {
  
      console.log(JSON.stringify(markers[index]));
      markers[index].setMap(null); // problem is here 
      // - setMap is not a function
      markers[index] = null;
  }
  
  
  GMaps.on('click',
      map.map,
      function(event) {
  
          markers.push(new Point(map.markers.length, event.latLng.lat(), event.latLng.lng()));
  
          var index = map.markers.length;
          var lat = event.latLng.lat();
          var lng = event.latLng.lng();
          map.addMarker({
              lat: lat,
              lng: lng,
              title: 'marker' + index,
              infoWindow: {
                  content: '&lt;p&gt;Details:'
                  + '&lt;p&gt;Latitude:' + event.latLng.lat() +  '&lt;/p&gt;'
                  + '&lt;p&gt;Longitude:' + event.latLng.lng() + '&lt;/p&gt;'+
                  '&lt;button id ="btnDeleteMarker" onclick=DeleteMarker(\'' + index + '\')&gt;Delete this stop&lt;/button&gt;'
              }
          });
          console.log(JSON.stringify(markers));
          map.markers[index].infoWindow.open(map.map, map.markers[index]);
  });
  </code></pre>
  
  <p>What is wrong? What should I know to use it in a proper way?</p>