class REXML::Text

u.to_s #-> "sean russell"
u = Text.new( "sean russell", false, nil, true )
t.to_s #-> "< & &s; russell"
t = Text.new( "< & &s; russell", false, nil, false )
t.to_s #-> "< & &s; russell"
t = Text.new( "< & sean russell", false, nil, false, ['s'] )
# entity "r" is defined to be "russell"
# Assume that the entity "s" is defined to be "sean", and that the

the entity filter set in the constructor.
entities that can be escaped, have been inserted. This method respects
escaped, meaning that it is a valid XML text node string, and all
Returns the string value of this text node. This string is always

def to_s
  return @string if @raw
  @normalized ||= Text::normalize( @string, doctype, @entity_filter )
end