python.samplers.PosSampler Node1 python.samplers.PosSampler + x + y + z + t - _x - _y - _z - _t + __init__() + x() + x() + y() + y() + z() + z() + t() + t() + shoot() Node2 python.samplers.Sampler + shoot() + __call__() Node2->Node1 Node3 object Node3->Node2