'A RVKC can be updated either via index or keyword access.'

def test_update_rvkc(self):

    self._test_header[0] = 3
    assert (self._test_header['DP1.NAXIS'] == 3.0)
    assert isinstance(self._test_header['DP1.NAXIS'], float)
    self._test_header['DP1.AXIS.1'] = 1.1
    assert (self._test_header['DP1.AXIS.1'] == 1.1)
