How to remove google map markers when using angular-google-maps directive

Question

So I'm having a problem removing the markers from my page when using angular-google-maps. here is the haml:

    %div.map-view
      %ui-gmap-google-map{control:"controller.map.control", center: "controller.map.center", zoom: "controller.map.zoom", options: "controller.mapOptions"}
        %ui-gmap-markers{control:"controller.markers", models: "controller.points", idkey: "'location_id'", coords: "'self'", icon: "'icon'", fit: "true", click: "'onClicked'"}

and then in my controller:

deleteMarkers: () =>
  if(@markers.getGMarkers().length != [].length)
    @markers.removeMany(@markers.getGMarkers())

That last line doesn't work because the removeMany method doesn't appear to be exposed on the control and I get this error:

TypeError: undefined is not a function

Any help is appreciated!