1 var Set = require('./es6.set')
2 , from = require('./_array-from-iterable')
3 , metadata = require('./_metadata')
4 , anObject = require('./_an-object')
5 , getPrototypeOf = require('./_object-gpo')
6 , ordinaryOwnMetadataKeys = metadata.keys
7 , toMetaKey = metadata.key;
9 var ordinaryMetadataKeys = function(O, P){
10 var oKeys = ordinaryOwnMetadataKeys(O, P)
11 , parent = getPrototypeOf(O);
12 if(parent === null)return oKeys;
13 var pKeys = ordinaryMetadataKeys(parent, P);
14 return pKeys.length ? oKeys.length ? from(new Set(oKeys.concat(pKeys))) : pKeys : oKeys;
17 metadata.exp({getMetadataKeys: function getMetadataKeys(target /*, targetKey */){
18 return ordinaryMetadataKeys(anObject(target), arguments.length < 2 ? undefined : toMetaKey(arguments[1]));