Comment 4 for bug 1997467

Here's a test case reproducer, which can be put into netplan's test_cli_get_set.py suite:

    def test_set_origin_hint_override(self):
        defaults = os.path.join(self.workdir.name, 'etc', 'netplan', '0-snapd-defaults.yaml')
        with open(defaults, 'w') as f:
            f.write('''network: {bridges: {br54: {dhcp4: true}}}''')
        self._set(['bridges.br54.dhcp4=false', '--origin-hint=90-snapd-config'])
        p = os.path.join(self.workdir.name, 'etc', 'netplan', '90-snapd-config.yaml')
        self.assertTrue(os.path.isfile(p))
        with open(p, 'r') as f:
            self.assertIs(False, yaml.safe_load(f)['network']['bridges']['br54']['dhcp4'])