Consider using s4 methods

[0xMuluh]

translate s3 methods to s4 methods, advantages include:

• Formal class definitions
• Multiple dispatch
• Developing large, complex systems
• Working with Bioconductor or other S4-based packages(ie tidyverse etc)

[TuomasBorman]

This is nice-to-have, but not crucial. I guess now the results are in list which is fine, but as @Daenarys8 noted, formal class could give benefits. (S7 class is preferred over S4)