title: Why is saveAs failing from read-only file?
body: <p>My application uses the google realtime API to define a custom document type, and includes a feature that allows you to create a copy of a document, using the API's <a href="https://developers.google.com/google-apps/realtime/reference/gapi.drive.realtime.Document.html#saveAs" rel="nofollow noreferrer">document.saveAs</a>.  One purpose of this is to allow users to make and edit personal copies of document templates that have been shared with them as read-only files.  I create a new document then use saveAs to copy the realtime document into it, something like this:</p>
  
  <pre><code>gapi.client.drive.files.create({
      resource: {
          mimeType: 'application/vnd.google-apps.drive-sdk',
          name: NEWNAME
  }).then((response) =&gt; {
      MYDOCUMENT.saveAs(response.result.id);
  });
  </code></pre>
  
  <p>This works perfectly with read-write files, but if the original file is read only it does not appear to save the realtime document into the new file. No error is reported but the resulting new file is empty.</p>
  
  <p>Is this is a bug or known limitation, or am I doing something wrong?</p>