gument to `create()` or `fixture()` to pass
the model:

```js
var bound = fixture('bound', {greeting: 'ohai thurr'});
```

## The problem being addressed

Consider the following `web-component-tester` test suite:

```html
<!doctype html>
<html>
<head>
  <title>some-element test suite</title>

  <link rel="import" href="../some-element.html">
</head>
<body>
  <some-element id="SomeElementForTesting"></some-element>
  <script>
describe('<some-element>', function () {
  var someElement;

  beforeEach(function 