These options will be used on objects of class 'S7_class'.
opts_S7_class(constructor = c("new_class", "next"), ...)An object of class <constructive_options/constructive_options_S7_class>
Depending on constructor, we construct the object as follows:
"new_class" (default): We build the object using S7::new_class().
"next" : Use the constructor for the next supported class.