i want to write a gtk widget in ruby.  i've tried lots of things like

class MrpWidget < Gtk::Widget
  def initialize
    super
  end
end

but it fails to initialize the object,

/widgettest.rb:7:in `initialize': can't instantiate class #<Class
0lx401a8748> (RuntimeError)
	from ./widgettest.rb:7:in `initialize'
	from ./widgettest.rb:13:in `new'
	from ./widgettest.rb:13

i've looked all over for examples of this, but can find anything
anywhere.
help!
martin.