# -*- encoding: utf-8 -*-
from abjad import *
import py.test


def test_NumberedPitchClass___slots___01():
    r'''Numbered pitch-classes are immutable.
    '''

    numbered_pitch_class = pitchtools.NumberedPitchClass(1)
    assert py.test.raises(AttributeError, "numbered_pitch_class.foo = 'bar'")
