angularjs - Add css style to gmap markers -

how can add css style ui-gmap markers?(angular.js)
example code:

<ui-gmap-markers docluster="true" click="'onclicked'" models="vm.map.markers" coords="'coords'" icon="'icon'" idkey="'id'" events="vm.mapevents" options="'options'" clusteroptions="vm.cluseroptions">     <ui-gmap-windows show="'showwindow'" closeclick="'closeclick'" ng-cloak>        <div data-ui-sref="display">             <span data-ng-non-bindable>test</span>        </div>      </ui-gmap-windows> </ui-gmap-markers> 

see this

edit

apparently, checked previous project , how used it:

<ui-gmap-markers control="vm.markercontrol" models="vm.markers" coords="'position'"     options="'options'" typeevents="vm.markerevents" type="'spider'" typeoptions="{keepspiderfied:true}" modelsbyref="false"> </ui-gmap-markers> 

vm.markers array or marker, , marker has option property. option has icon property:

marker = {   option: {     icon : "icon.png",     labelclass : "some-class"   } } 

edit added labelclass