code: function applyAllowedRuleToArray( itemsRule, items, validItems ) {
  		if ( !itemsRule )
  			return false;
  
  		// True means that all elements of array are accepted (the asterix was used for classes).
  		if ( itemsRule === true )
  			return true;
  
  		for ( var i = 0, l = items.length, item; i < l; ++i ) {
  			item = items[ i ];
  			if ( !validItems[ item ] )
  				validItems[ item ] = itemsRule( item );
  		}
  
  		return false;
  	}
docs: Apply itemsRule to items (only classes are kept in array). Push accepted items to validItems array. Return true when all items are valid.