These options will be used on objects of class 'S4'.
opts_S4(constructor = c("new", "prototype"), ...)An object of class <constructive_options/constructive_options_S4>
String. Name of the function used to construct the object, see Details section.
Additional options used by user defined constructors through the opts object
Depending on constructor, we construct the object as follows:
"new" (default): We build the function using new() if possible.
If the class has a "initialize" method we have no practical way to
reverse-engineer the inputs so we fall back to the "prototype" constructor
"prototype" : We start from getClass("S4")@prototype and add attributes.