Developing Pass-Through Types

These are the fields you need to overload,
and this is how you overload them

https://github.com/JuliaText/CorpusLoaders.jl/blob/1a011a08b6072242604b6fd2ebcdf5ed258b6f44/src/types.jl#L5-L23

That one is done by declaring an abstract type.
But of-course you can do it directly,
or via metaprogramming