Function keys

test/expect.js:796–810

(obj)

  }

  function keys (obj) {
    if (Object.keys) {
      return Object.keys(obj);
    }

    var keys = [];

    for (var i in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, i)) {
        keys.push(i);
      }
    }

    return keys;
  }

  function map (arr, mapper, that) {
    if (Array.prototype.map) {