'Regression test for https://github.com/astropy/astropy/pull/4514
Tests that columns with the X (bit array) format can be deep-copied.'

def test_x_column_deepcopy(self):

    c = fits.Column('xcol', format='5X', array=[1, 0, 0, 1, 0])
    c2 = copy.deepcopy(c)
    assert (c2.name == c.name)
    assert (c2.format == c.format)
    assert np.all((c2.array == c.array))
