code: def <<(text)
           if !last.nil? and last.respond_to?(:text=)
              last.append(text)
           else
              self.store(TextNode.new(self, text))
           end
        end
docs: This is the constructor for the CommandNode class.
  
   ==== Parameters
   parent::  A reference to the node that owns the new node.
   prefix::  A String containing the prefix text for the command.
   suffix::  A String containing the suffix text for the command. Defaults
             to nil.
   split::   A boolean to indicate whether the prefix and suffix should
             be written to separate lines whether the node is converted
             to RTF. Defaults to true.
   wrap::    A boolean to indicate whether the prefix and suffix should
             be wrapped in curly braces. Defaults to true.
   This method adds text to a command node. If the last child node of the
   target node is a TextNode then the text is appended to that. Otherwise
   a new TextNode is created and append to the node.
  
   ==== Parameters
   text::  The String of text to be written to the node.