Create a waiver object.
Details
This object is used to represent that the user has not manually
specified a setting, and so defaults should be used. By explicitly
using a new_waiver(), this means that NULL objects can be a
valid setting. The use of a waiver object was inspired by the
ggplot2 package.
Examples
# create new waiver object
w <- new_waiver()
# print object
print(w)
#> list()
#> attr(,"class")
#> [1] "Waiver"