title: Why does getMatrixTrait("transform") throw a DOMException:NOT_SUPPORTED_ERR?
body: <p>It is said that <code>DOMException - with error code NOT_SUPPORTED_ERR if the requested trait is not supported on this element or null.</code></p>
  
  <p>I am trying to flip my SVG image horizontally, but I'm stuck with this error.</p>
  
  <pre><code>InputStream svgStream = getClass().getResourceAsStream(path);
  SVGImage svgImage = (SVGImage) (SVGImage.createImage(svgStream, null));
  SVGSVGElement myEl = (SVGSVGElement) svgImage.getDocument().getDocumentElement());
  SVGMatrix transformMatrix = myEl.getScreenCTM();
  transformMatrix = transformMatrix.mTranslate(100f, 0f);
  myEl.setMatrixTrait("transform", transformMatrix);
  </code></pre>