docs: def as_dataset(obj):
      """Cast the given object to a Dataset.
  
      Handles Datasets, DataArrays and dictionaries of variables. A new Dataset
      object is only created if the provided object is not already one.
      """
      if hasattr(obj, 'to_dataset'):
          obj = obj.to_dataset()
      if not isinstance(obj, Dataset):
          obj = Dataset(obj)
      return obj