code: function ( obj ) {
  		var result = [];
  
  		array.each( obj, function ( i ) {
  			array.add( result, i );
  		});
  
  		return result;
  	}
docs: Returns an Array of unique indices of `obj`
  
  @method unique
  @param  {Array} obj Array to parse
  @return {Array}     Array of unique indices