...
zero or more library names to shim binding each exported
variable to the binder; if a library name is specified in a named
list format (for example shim(s4='stats4',callback=function(s4.AIC)))
all exported variable names from that library will be prepended with
that name and a dot (as in the example); if a library cannot be
loaded, no bindings are created for that library and no errors are
thrown (but there is an error to console as reported by
requireNamespace)