an element that has options ( node, edge or graph )
# File rdoc/dot.rb, line 92 def initialize( params = {}, option_list = [] ) super( params ) @name = params['name'] ? params['name'] : nil @parent = params['parent'] ? params['parent'] : nil @options = {} option_list.each{ |i| @options[i] = params[i] if params[i] } @options['label'] ||= @name if @name != 'node' end