def test_empty_message_should_yield_empty():
seq = ['']
expected = []
assert expected == list(camera_connected(seq))
def test_add_message_should_yield_true():
seq = ['®add Nikon D3000']
expected = [True]
assert expected == list(camera_connected(seq))
def test_add_remove_message_should_yield_true_false():
seq = ['®add Nikon D3000', '®remove Nikon D3000']
expected = [True, False]
assert expected == list(camera_connected(seq))
def test_remove_message_should_yield_false():
seq = ['®remove Nikon D3000']
expected = [False]
assert expected == list(camera_connected(seq))
