1
 2/**
 3 * Gets the keys for an object.
 4 *
 5 * @return {Array} keys
 6 * @api private
 7 */
 8
 9module.exports = Object.keys || function keys (obj){
10  var arr = [];
11  var has = Object.prototype.hasOwnProperty;
12
13  for (var i in obj) {
14    if (has.call(obj, i)) {
15      arr.push(i);
16    }
17  }
18  return arr;
19};