import hasOwnProp from './has-own-prop'; export default function extend(a, b) { for (var i in b) { if (hasOwnProp(b, i)) { a[i] = b[i]; } } if (hasOwnProp(b, 'toString')) { a.toString = b.toString; } if (hasOwnProp(b, 'valueOf')) { a.valueOf = b.valueOf; } return a; }