'Fail silently for methods that raise an exception with a
`silent_variable_failure` attribute'

@setup({'filter-syntax13': '1{{    var.method3    }}2'})
def test_filter_syntax13(self):

    output = self.engine.render_to_string('filter-syntax13', {'var': SomeClass()})
    if self.engine.string_if_invalid:
        self.assertEqual(output, '1INVALID2')
    else:
        self.assertEqual(output, '12')
