> tbl_at_vars(iris, raw(3))
Error: `.vars` must be a character/numeric vector or a `vars()` object, not a raw vector.

> tbl_if_vars(iris, list(identity, force), environment())
Error: `.predicate` must have length 1, not 2.

> .funs <- as_fun_list(list(identity, force), caller_env())
> tbl_if_vars(iris, .funs, environment())
Error: `.predicate` must have length 1, not 2.

