Right now, all the field filters return a `FieldResult`, which contains a `vtkm::cont::Field` class. However, in many cases this is an inconvenient form. You really want fields attached to a `vtkm::cont::DataSet` object so that they can be further processed. It is a pain for users to have to get the `Field` and build a new `DataSet` on their own. It can also be confusing to new users. Also, it is easy to make mistakes (for example, getting the association wrong). It would be better if the filter built a `DataSet` containing the new field (along with the old fields).