Mat Utter

Results 11 issues of Mat Utter

## Description The containment check, e.g. `foo in bar`, does not use the `__contains__` operator in python, but instead it uses `__len__` and then multiple calls to `__getitem__` in [ops.rs#L456](https://github.com/mitsuhiko/minijinja/blob/513f6f20a03bf86995950341bdbdc032397308a0/minijinja/src/value/ops.rs#L456)....