make getSupportedTypes to copy the structure

[Antonio Musolino]

We can refactor the getSupportedTypes method; initially, I make it return the structure without manipulating it for performance reasons. But now, I think it is better to copy the data structure even if there are performance degradations. Because if you modify the returned output, you can break the code.
WDYT! @simonecorsi @dnlup

[Simone Corsi]

If you want to avoid external users to modify it you could also freeze it, Types enum compiles to an object literal

[dnlup]

Yes, if the object is not nested freeze would work in this case 😉

[Antonio Musolino]

👍