code: function MarkerManager(map, opt_opts) {
    var me = this;
    me.map_ = map;
    me.mapZoom_ = map.getZoom();
  
    me.projectionHelper_ = new ProjectionHelperOverlay(map);
    google.maps.event.addListener(me.projectionHelper_, 'ready', function () {
      me.projection_ = this.getProjection();
      me.initialize(map, opt_opts);
    });
  }
docs: @name MarkerManagerOptions
  @class This class represents optional arguments to the {@link MarkerManager}
  constructor.
  @property {Number} maxZoom Sets the maximum zoom level monitored by a
  marker manager. If not given, the manager assumes the maximum map zoom
  level. This value is also used when markers are added to the manager
  without the optional {@link maxZoom} parameter.
  @property {Number} borderPadding Specifies, in pixels, the extra padding
  outside the map's current viewport monitored by a manager. Markers that
  fall within this padding are added to the map, even if they are not fully
  visible.
  @property {Boolean} trackMarkers=false Indicates whether or not a marker
  manager should track markers' movements. If you wish to move managed
  markers using the {@link setPoint}/{@link setLatLng} methods,
  this option should be set to {@link true}.
   
  Creates a new MarkerManager that will show/hide markers on a map.
  
  Events:
  @event changed (Parameters: shown bounds, shown markers) Notify listeners when the state of what is displayed changes.
  @event loaded MarkerManager has succesfully been initialized.
  
  @constructor
  @param {Map} map The map to manage.
  @param {Object} opt_opts A container for optional arguments:
  {Number} maxZoom The maximum zoom level for which to create tiles.
  {Number} borderPadding The width in pixels beyond the map border,
  where markers should be display.
  {Boolean} trackMarkers Whether or not this manager should track marker
  movements.