def METHOD_NAME(self):
    type_ = ['Fiducial', 'ReferenceElectrode', 'CoilPos']
    coordinates = np.array([[1, 2, 3],
                            [1.2, 2.4, 7.1],
                            [1, 2, 3]])
    header = []
    name = ['fiducial',  None, 'coil']
    extra_cols = [['a2'], None, ['comment']]
    extra = [None, None, np.array([4., 5., 6., 7., 8., 9., 10], dtype=float)]
    f = tempfile.NamedTemporaryFile(delete=False)
    csv_reader.write_csv_positions(f.name, type_, coordinates, name, extra, extra_cols, header)
    with open(f.name, 'r') as f:
        assert f.readline().strip() == 'Fiducial,1.0,2.0,3.0,fiducial,a2'
        assert f.readline().strip() == 'ReferenceElectrode,1.2,2.4,7.1'
        assert f.readline().strip() == \
            'CoilPos,1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0,10.0,coil,comment'