function element = top(self)
%return 'top' node
% usage
%   data = top(stack)

% $Id: get.m 416 2009-02-13 07:55:41Z jgrelet $

% return object prepared in data
% ------------------------------

if isempty(self.stack_pointer)
  element = {};
else
  element = data(self.stack_pointer);
end
end