code: private void doIndent ()
      throws SAXException
      {
          int n = indentStep * stateStack.size();
          if (n > 0) {
              char ch[] = new char[n];
              for (int i = 0; i < n; i++) {
                  ch[i] = INDENT_CHAR;
              }
              super.characters(ch, 0, n);
          }
      }
docs: Add indentation for the current level.
  
  @exception org.xml.sax.SAXException If a filter
  further down the chain raises an exception.