up = graph.add_component(MySource, 'down')
down = graph.add_component(MySink, 'up')
graph.connect_ports(up.output_ports['out'], down.input_ports['in'])
up = graph.add_component(MySource, 'down')
down = graph.add_component(MySink, 'up')
graph.connect_ports(up.output_ports['out'], down.input_ports['in'])