.Class - OtagJS/Otag GitHub Wiki
.Class( classes Array|String, remove Boolean )
Adds/Removes classes to/from an Element
var Elem='.this.is.an.Elem'.Class('an',1); // remove the 'an' class;
O.ready.then(b=>b.append(Elem));
<div class="this is Elem"></div>
Elem.Class(['brand','new']);
<div class="this is Elem brand new"></div>