check_formula_list: Check/convert formula to list
Description
Check if an object is a list of formulas and/or NULL elements and convert
it to a list if it is a formula object.
Usage
check_formula_list(formula, convert = TRUE)
Arguments
- formula
any object
- convert
logical; should the input be converted to a list?
Details
Internal function; used in many help functions, get_refs, *_imp, predict
(2022-02-05)