tidy(NULL), glance(NULL) and augment(NULL) all return an empty
tibble::tibble. This empty tibble can be treated a tibble with zero
rows, making it convenient to combine with other tibbles using
functions like purrr::map_df() on lists of potentially NULL objects.
# S3 method for `NULL`
tidy(x, ...)# S3 method for `NULL`
glance(x, ...)
# S3 method for `NULL`
augment(x, ...)
An empty tibble::tibble.
The value NULL.
Additional arguments (not used).