Was previously seeing:

```
  <frozen _collections_abc>:801: FutureWarning: The return type of `Dataset.dims` will be changed to return a set of dimension names in future, in order to be more consistent with `DataArray.dims`. To access a mapping from dimension names to lengths, please use `Dataset.sizes`.
```

Now:

```
  /Users/maximilian/workspace/xarray/xarray/tests/test_dataset.py:701: FutureWarning: The return type of `Dataset.dims` will be changed to return a set of dimension names in future, in order to be more consistent with `DataArray.dims`. To access a mapping from dimension names to lengths, please use `Dataset.sizes`.
    assert ds.dims == ds.sizes
```

It's a heuristic, so not perfect, but I think very likely to be accurate. Any contrary cases very welcome...