def circuit(w, x=None):
    qml.RX(x[0], wires=[0])
    qml.RX(x[1], wires=[1])
    return (qml.expval(qml.PauliZ(0)), qml.expval(qml.PauliZ(1)))
def circuit(w, x=None):
    qml.RX(x[0], wires=[0])
    qml.RX(x[1], wires=[1])
    return (qml.expval(qml.PauliZ(0)), qml.expval(qml.PauliZ(1)))