Whether to include the output of R0() and run() as incidences of the classes

[hfldai]

In development, methods or functionalities written for S4 classes often return an object of the corresponding S4 class, and add/update the corresponding incidences into the object accordingly. In this way, one can access the computed values within the object by e.g. object@value. In our classes, we already have methods like initial_conditions<- and transmission_parameters<- working in this way.

Shall we do the same for the R0() and run() methods? Currently they return a value and a list, respectively. In other words, would we want to include the simulation output and R0 value as incidences of our classes?

[ben18785]

Decided to stay with R0 as returning a value since it's easier for users.