title: Can we find out whether a Google map has been initialized?
body: <p>Say we've initialize a map with some code:</p>
  
  <pre><code>function initialize() {
      var mapOptions = {
          center: new google.maps.LatLng(-34.397, 150.644),
          zoom: 8,
          mapTypeId: google.maps.MapTypeId.ROADMAP
      };
      var map = new google.maps.Map(document.getElementById("map-canvas-0"),
          mapOptions);
  }
  </code></pre>
  
  <p>Is there an easy way to determine whether a particular map on the page has been initialized (in this case, the map located at id="map-canvas-0")?</p>
  
  <p>I can think of some ways using hidden fields, but I was hoping there was a simpler way.</p>