How to set a form as pristine? : <ul>
<li>The form that represents entity state is being edited (turns dirty)</li>
<li>The form is being submitted and entity state is now aligned with the form state which means that the form should now be set as pristine.</li>
</ul>

<p>How do we do that? 
There was <code>$setPristine()</code> in ng1.
Btw, I'm talking about <code>ControlGroup</code> type of form.</p>
