code: public void appendTag(final Appendable appendable, final CharSequence tagName,
  						  final String content) throws IOException {
  		appendable.append('<').append(tagName).append('>')
  				.append(this.escaper.escapeXMLContent(content)).append("</")
  				.append(tagName).append('>');
  	}
docs: Append a content inside a tag
  @param appendable the destination
  @param tagName the tag name
  @param content the content
  @throws IOException if an I/O error occurs