- Implement to_s (e.g. `#<struct Person full_name=nil, age=nil>` for `Person` class )
- Fix issue with ability to handle cycles in to_s/inspect implementation (printing #<struct #<Class:0x00007ff874073590>:...> when self object is encountered within attributes)
- Fix issue with ability to handle cycles in hash implementation, including Opal
- Fix issue with ability to handle cycles in equality
- Fix issue with ability to handle cycles in equivalence