'Tests for basic validation of \'exclude\' option values (#12689)'

def test_exclude_values(self):

    class ExcludedFields1(admin.ModelAdmin, ):
        exclude = 'foo'
    self.assertRaisesMessage(ImproperlyConfigured, "'ExcludedFields1.exclude'    must    be    a    list    or    tuple.", ExcludedFields1.validate, Book)
