How to make md-contact-chips readonly to true
<p>The <a href="https://material.angularjs.org/latest/api/directive/mdChips" rel="nofollow">md-chips</a> has <strong>readonly</strong> attribute that disables list manipulation (deleting or adding list items), hiding the input and delete buttons. If no ng-model is provided, the chips will automatically be marked as readonly. </p>

<p>But the <a href="https://material.angularjs.org/latest/api/directive/mdContactChips" rel="nofollow">md-contacts-chips</a> have no <strong>readonly</strong> attribute.</p>

<p>How am I able to disable the remove button for the chips?</p>