Macro impl_scale_via_ark 

macro_rules! impl_scale_via_ark {
    ($t:ty) => { ... };
}

Implement scale::{Encode,Decode} by delegation to ArkScale, but lacks support for polymorphic code.

You should manually provide MaxEncodedLen for weights.

impl_scale_via_ark!(MyArkworksType);
 
impl ark_scale::MaxEncodedLen for MyArkworksType 
{
    fn max_encoded_len() -> usize {
        256
    }
}