# File gtk/sample/gtk-demo/cairo-long-lines.rb, line 19
    def draw(cr)
      cr.move_to(0.1, -50)
      cr.line_to(0.1, 50)
      cr.set_source_rgba(1, 0, 0)
      cr.stroke
      
      cr.move_to(0.2, -60)
      cr.line_to(0.2, 60)
      cr.set_source_rgba(1, 1, 0)
      cr.stroke
      
      cr.move_to(0.3, -70)
      cr.line_to(0.3, 70)
      cr.set_source_rgba(0, 1, 0)
      cr.stroke
      
      cr.move_to(0.4, -80)
      cr.line_to(0.4, 80)
      cr.set_source_rgba(0, 0, 1)
      cr.stroke
    end