code: function ( obj, arg ) {
  		array.each( arg, function ( i ) {
  			array.add( obj, i );
  		});
  
  		return obj;
  	}
docs: Merges `arg` into `obj`, excluding duplicate indices
  
  @method merge
  @param  {Array} obj Array to receive indices
  @param  {Array} arg Array to merge
  @return {Array}     obj