docs: function (prefix, callback, marker, contents) {
  
  			var search = {
  				Prefix: prefix, 
  				Bucket: options.bucket
  			};
  
  			if (marker) {
  				search.Marker = marker;
  			}
  
  			s3.listObjects(search, function (err, list) { 
  
  				if (!err) {
  
  					var objects = (contents) ? contents.concat(list.Contents) : list.Contents;
  
  					if (list.IsTruncated) {
  						var new_marker = _.last(list.Contents).Key;
  						listObjects(prefix, callback, new_marker, objects);
  					}
  					else {
  						callback(_.uniq(objects, function (o) { return o.Key; }));
  					}
  				}
  				else {
  					grunt.fatal('Failed to list content of bucket ' + options.bucket + '\n' + err);
  				}
  			});
  		}