collect-extracts.md
In workflowsets: Create a Collection of 'tidymodels' Workflows

collect_extracts fails gracefully without .extracts column

Code
  collect_extracts(wflow_set_trained)
Condition
  Error in `dplyr::mutate()`:
  i In argument: `extracts = list(collect_extracts(result))`.
  i In row 1.
  Caused by error in `collect_extracts()`:
  ! The `.extracts` column does not exist.
  i Please supply a control object (`?tune::control_grid()`) with a non-`NULL` `extract` argument during resample fitting.