title: failed to set parent for annotation in MATLAB
body: <p>I have created a figure in MATLAB, and an axis inside the figure. 
  I want to have annotation in the axis, so that it would be easier for me to define its relative position.</p>
  
  <p>But I failed when I use </p>
  
  <pre><code>numRec = annotation('rectangle','Parent', app.DisplayPath)
  </code></pre>
  
  <p>where the app.DisplayPath is the axis I mentioned above.</p>
  
  <p>The console gives the following warning</p>
  
  <blockquote>
    <p>Warning: Cannot specify the parent of an annotation object - Ignoring
    the parent property</p>
  </blockquote>
  
  <p>I am wondering if there is anyway I could set the annotation's parent as the axis? I find that annotation has property of Parent on documentation, but it says: </p>
  
  <blockquote>
    <p>Parent: [1x1 AnnotationPane]</p>
  </blockquote>
  
  <p>Any hints are appreciated!!</p>