These options will be used on objects of class 'S7_any'.
opts_S7_any(constructor = c("class_any", "next"), ...)An object of class <constructive_options/constructive_options_S7_any>
Depending on constructor, we construct the object as follows:
"class_any" (default): We build the object using S7::class_any().
"next" : Use the constructor for the next supported class.