It’s often a good idea to extend functionality like this. You might be interested in the @forward macro from the Lazy.jl package.
Also be careful of your types here, you might not get specialisation due to the abstract type. Consider using a generic:
struct NormalizedMine{T<:AbstractMine,Q}<:AbstractMine
nn::T
normalization_factor::Q
end
You don’t need the Q type, especially if you know the concrete type already.