import pyutilib.workflow

# @ex:
class TaskAA(pyutilib.workflow.Task):

    def __init__(self, *args, **kwds):
        """Constructor."""
        pyutilib.workflow.Task.__init__(self, *args, **kwds)
        self.inputs.declare('x')
        self.inputs.declare('y')
        self.add_argument('--x', dest='x', type=int)
        self.add_argument('--y', dest='y', type=int)
        self.outputs.declare('z')

    def execute(self):
        """Compute the sum of the inputs."""
        self.z = self.x + self.y

AA = TaskAA()
w = pyutilib.workflow.Workflow()
w.add(AA)
w.set_options(['--x=1', '--y=3', '--bad=4'])
print(w())
# @:ex