Q: given a node, `a` in this case, how to know if its type is a container or not (list or dict in Python)?
https://github.com/py2many/py2many/blob/affbf1b6942a72af62dc6a7be353bb118546d189/tests/test_unsupported.py#L127

The last assert need to be translated into D as:
```
  assert(not(len(a) != 0))
```

In this case, given a node, `a` in this case, how to know if its type is a container or not (list or dict in Python)?

And also how to know its parent scope, i.e. `not` in this case, is a bool type?

Thanks.
