unbinding of `this` for `import { x } from "y";` syntax

foo.js

let foo = {
  alpha () {
    return this.bravo();
  },
  bravo () {
    return "charlie";
  }
}

export default foo;

test.js

import { alpha } from "foo";
alpha(); // Uncaught TypeError: Cannot read property 'bravo' of undefined

// webpack transpilation:
var _foo = __webpack_require__(3);
(0, _foo.alpha)();

// ================================

import foo from "foo";
foo.alpha(); // "charlie"

// webpack transpilation:
var _foo = __webpack_require__(3);
var _foo2 = _interopRequireDefault(_foo);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
_foo2.default.alpha();