'Test len()/__len__.
Args:
data: The data to write before checking if the length equals
len(data).'

@pytest.mark.parametrize('data', ['12345', ''])
def test_len(self, pyqiodev, data):

    pyqiodev.open(QIODevice.WriteOnly)
    pyqiodev.write(data)
    assert (len(pyqiodev) == len(data))
