def test_is_volume_muted_children_only(self):
        config = self.config_children_only
        universal.validate_config(config)

        ump = universal.UniversalMediaPlayer(self.hass, **config)
        ump.entity_id = media_player.ENTITY_ID_FORMAT.format(config['name'])
        ump.update()

        self.assertFalse(ump.is_volume_muted)

        self.mock_mp_1._state = STATE_PLAYING
        self.mock_mp_1.update_ha_state()
        ump.update()
        self.assertFalse(ump.is_volume_muted)

        self.mock_mp_1._is_volume_muted = True
        self.mock_mp_1.update_ha_state()
        ump.update()
        self.assertTrue(ump.is_volume_muted)
Test is volume muted property w/ children only.
dataset/ETHPy150Open home-assistant/home-assistant/tests/components/media_player/test_universal.py/TestMediaPlayer.test_is_volume_muted_children_only