title: Animating nebular sidebar component
body: <p>I am using nebular sidebar component, what i'm trying to do is animating the opening and the closing of the sidebar.
  I checked the sidebar API but i didn't find anything that can do that ? I tried to apply css transition on the class but it didn't work, so how can i approach this ?</p>
  
  <pre><code>&lt;nb-layout&gt;
  
    &lt;nb-layout-header subheader&gt;
      &lt;app-navbar style="width: 100%"&gt;&lt;/app-navbar&gt;
    &lt;/nb-layout-header&gt;
  
    &lt;nb-sidebar [state]="'compacted'"&gt;
      &lt;app-sidenav-menu&gt;&lt;/app-sidenav-menu&gt;
    &lt;/nb-sidebar&gt;
  
    &lt;nb-layout-column&gt;
      &lt;router-outlet&gt;&lt;/router-outlet&gt;
    &lt;/nb-layout-column&gt;
  &lt;/nb-layout&gt;
  </code></pre>