@qml.qnode(dev, interface='tf')
def g(y):
    qml.RY(y, wires=0)
    return qml.expval(qml.PauliX(0))
@qml.qnode(dev, interface='tf')
def g(y):
    qml.RY(y, wires=0)
    return qml.expval(qml.PauliX(0))