Demonstrates Quantum Fourier transform.

def main():
    """Demonstrates Quantum Fourier transform.
    """
    # Create circuit
    qft_circuit = generate_2x2_grid_qft_circuit()
    print('Circuit:')
    print(qft_circuit)
    # Simulate and collect final_state
    simulator = cirq.Simulator()
    result = simulator.simulate(qft_circuit)
    print()
    print('FinalState')
    print(np.around(result.final_state, 3))