Generic classes with type parameters parsing/serializing

Aloha!

For a big project of mine my data is stored as such:

```
abstract class A {
T1 first;
T2 second;
...other simple fields...
}

class B{
}
```

Since the scope for the data is so wide there are N number of classes that all depend on A like this. In GSON I use TypeAdapters to include the class name of each subclass in the json so that it can be read back properly, Id like to see something similar in LoganSquare.

I cannot get it to work the way LoganSquare is built at the moment (If its supported at all?) as it always tries to create instances of A directly.

Thanks!

Start by examining LoganSquare's generated parsing and serialization handling for abstract and generic classes, then compare it with the issue's A and B example. Check how GSON TypeAdapters provide subclass type information. Done means subclasses can be serialized with their class identity and read back without trying to instantiate A directly.

Written by the indexing model from the issue text.