code: function(obj) {
  			var result = {};
  			var keys = this.toArray(arguments, 1);
  			Object.keys(obj).forEach(function(key) {
  				if (~keys.indexOf(key)) {
  					result[key] = obj[key];
  				}
  			});
  			return result;
  		}
docs: Return a copy of the object, filtered to only have values for
  the whitelisted keys.
  @param  {Object} obj
  @return {Object}