The setPackages function lets users manually declare packages
that R worker processes need to load before running their tasks.
setPackages(packages = c())The value of packages is invisibly returned (this function is used for its side effect).
A character vector of package names.
The foreach function includes a similar .packages parameter.
Defines a way to set the foreach .packages option for users without direct access
to the foreach function, for example, when foreach is used
inside another package.