{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"let"}]}
    let impl_def = ctx.find_node_at_offset::<ast::Impl>()?.clone_for_update();
pub(crate) fn generate_mut_trait_impl(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
    let indent = impl_def.indent_level();