class REXML::Text

'text << "XXX" << "YYY"'.
+returns+ the text itself to enable method chain like

of this text node.
Appends text to this text node. The text is appended in the +raw+ mode

def <<( to_append )
  @string << to_append.gsub( /\r\n?/, "\n" )
  clear_cache
  self
end