title: What is md-component-id?
body: <p>The <a href="https://material.angularjs.org/latest/api/directive/mdSidenav" rel="nofollow noreferrer">documentation</a> on the <code>md-sidenav</code> directive states:</p>
  
  <blockquote>
    <p>md-component-id - string - componentId to use with $mdSidenav service.</p>
  </blockquote>
  
  <ul>
  <li>What is componentId?</li>
  <li>Which values are available besides the obvious <code>left</code> and <code>right</code> (e.g., in <a href="http://fuse-angular-material.withinpixels.com/mail/inbox" rel="nofollow noreferrer">Fuse template</a>, a value of <code>main-sidenav</code> is used)?</li>
  <li>Is it optional?</li>
  <li>How does it affect the sidebar?</li>
  </ul>