$.GlobalOptionsFun      Get option value by dollar symbol
$.InternalOptionValue   Get value of other options
$<-.GlobalOptionsFun    Set option value by dollar symbol
.DollarNames.GlobalOptionsFun
                        The .DollarNames method for the
                        GlobalOptionsFun class
.v                      Get value of other options
[.GlobalOptionsFun      Get a single GlobalOption object
[[.GlobalOptionsFun     Get option value by subset operator
[[<-.GlobalOptionsFun   Set option value by subset operator
dump_opt                Print all fields of a single option
print.GlobalOptionsFun
                        Print the GlobalOptionsFun object
setGlobalOptions        Produce a function which can get or set global
                        options
set_opt                 Produce a function which can get or set global
                        options
