title: Mock context provider
body: <p>I am trying to test a component that uses context from a provider component.</p>
  
  <pre class="lang-tsx prettyprint-override"><code>import { MuiPickersUtilsProvider } from 'material-ui-pickers';
  import DateFnsUtils from '@date-io/date-fns';
  render((
    &lt;MuiPickersUtilsProvider utils={DateFnsUtils}&gt;
      &lt;App /&gt;
    &lt;/MuiPickersUtilsProvider&gt;
  ), document.getElementById('root'));
  </code></pre>
  
  <p>I've tried setting the context this way, but it is still complaining that context utils is not found.
  AppTest</p>
  
  <pre><code>it('renders App Component', () =&gt; {
      const context = { utils: DateFnsUtils };
  
      const wrapper = shallow(&lt;App/&gt;, { context });
  
      expect(wrapper.find(App)).toHaveLength(1);
  });
  </code></pre>
  
  <p>Error: Uncaught [Error: Can not find utils in context. You either a) forgot to wrap your component tree in MuiPickersUtilsProvider; or b) mixed named and direct file imports.  Recommendation: use named imports from the module index.</p>