Function gen_bridge_trait_impl 

pub fn gen_bridge_trait_impl(
    spec: &TraitBridgeSpec<'_>,
    generator: &dyn TraitBridgeGenerator,
) -> String

Generate impl Trait for Wrapper dispatching each method through the generator.

Methods with has_default_impl = true are NOT emitted — the trait’s own default implementation is used instead. Only required (non-defaulted) own methods get a generated vtable-forwarding body.