console . log ( 'load::bg' ) ; window . addEventListener ( 'load' , ( ) => { window . postMessage ( { _arkhamCall : { method : 'storeClasses' } } , '*' ) ; } ) ; window . addEventListener ( 'message' , ( event ) => { const { data = { } , source } = event ; if ( source !== window ) { return ; } chrome . runtime . sendMessage ( data ) ; } ) ;