{"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"from_placeholder_idx,"}]}
    from_placeholder_idx, generics::generics, mapping::ToChalk, to_chalk_trait_id,
    db::HirDatabase, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
    utils::ClosureSubst,