code: function klassNames_() {
    var bKlass = [];
  
    for (var i = 0; i < arguments.length; i++) {
      var arg = arguments[i];
      if (!arg) continue;
  
      var argType = typeof arg === 'undefined' ? 'undefined' : _typeof(arg);
      if (argType === 'string' || argType === 'number') bKlass.push(arg);else if (Array.isArray(arg)) bKlass.push(klassNames_.apply(null, arg));else if (argType === 'object') {
        for (var key in arg) {
          if (hasOwn_.call(arg, key) && arg[key]) bKlass.push(key);
        }
      }
    }
  
    return bKlass.join(' ');
  }
docs: sClsList = klassNames_('cls_a') sClsList = klassNames_(['cls_b','cls_c']) sClsList = klassNames_({cls_d:true,cls_e:false}) sClsList = klassNames_('cls_a',['cls_b'],{cls_c:true})