What is the issue with `check_outcome()` function? Why does it indicate that the outcome needs to be a factor in a classification model?

edit

It is not clear from the given information what precise issue there might be with the check_outcome() function. However, the fact that it checks whether the outcome variable is a factor suggests that it is checking whether the outcome is a categorical variable, which is often the case in classification models. In classification models, the outcome variable typically represents a class label that indicates the predicted category for each observation. Factors are a common way of representing categorical data in R, so it may be that the check_outcome() function is simply checking whether the outcome is in a format that is suitable for use in a classification model.