title: Material expansion panel content - ng-template?
body: <p>I have the following code, which I stole from here:
  <a href="https://github.com/angular/material2/blob/master/src/demo-app/expansion/expansion-demo.html" rel="nofollow noreferrer">https://github.com/angular/material2/blob/master/src/demo-app/expansion/expansion-demo.html</a></p>
  
  <pre><code>  &lt;mat-expansion-panel class="mat-expansion-demo-width" #myPanel&gt;
  
      &lt;mat-expansion-panel-header [expandedHeight]="expandedHeight" [collapsedHeight]="collapsedHeight"&gt;
        &lt;mat-panel-description&gt;Click here to change view format.&lt;/mat-panel-description&gt;
        &lt;mat-panel-title&gt;View Controls&lt;/mat-panel-title&gt;
      &lt;/mat-expansion-panel-header&gt;
  
      &lt;ng-template matExpansionPanelContent&gt;
        This is the content text that makes sense here.
        &lt;mat-checkbox&gt;Trigger a ripple&lt;/mat-checkbox&gt;
      &lt;/ng-template&gt;
  
      foo bar baz
  
      &lt;mat-action-row&gt;
        &lt;button mat-button (click)="myPanel.expanded = false"&gt;CANCEL&lt;/button&gt;
      &lt;/mat-action-row&gt;
    &lt;/mat-expansion-panel&gt;
  </code></pre>
  
  <p>One question - I am confused, because the content inside the <code>&lt;ng-template&gt;</code> tag does not display, however "foo bar baz" does display. So what is the purpose of the content inside <code>&lt;ng-template&gt;</code> and why is it not displaying?</p>