{"ast_node_type":"other","tokens":[{"end":85,"kind":"keyword","start":0,"text":"TagEncoding::Niche"}]}
        TagEncoding::Niche { untagged_variant, ref niche_variants, niche_start } => {
        }
            let relative_max = niche_variants.end().as_u32() - niche_variants.start().as_u32();