/**
  * Create a highlighted range on the previewers document with the given line, column, length and
  * key.
  *
  * @param line the line
  * @param column the column
  * @param length the length
  * @param key the key
  * @return the highlighted range
  */
 private HighlightedRange createHighlightedRange(int line, int column, int length, String key) {
   try {
     IDocument document = fPreviewViewer.getDocument();
     int offset = document.getLineOffset(line) + column;
     return new HighlightedRange(offset, length, key);
   } catch (BadLocationException x) {
     CUIPlugin.log(x);
   }
   return null;
 }