code: public Drawable getMarker(final int stateBitset) {
  		// marker not specified
  		if (mMarker == null) {
  			return null;
  		}
  
  		// set marker state appropriately
  		setState(mMarker, stateBitset);
  		return mMarker;
  	}
docs: /*
  (copied from Google API docs) Returns the marker that should be used when drawing this item
  on the map. A null value means that the default marker should be drawn. Different markers can
  be returned for different states. The different markers can have different bounds. The
  default behavior is to call {@link setState(android.graphics.drawable.Drawable, int)} on the
  overlay item's marker, if it exists, and then return it.
  
  @param stateBitset The current state.
  
  @return The marker for the current state, or null if the default marker for the overlay
  should be used.