syntax_data: {"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"parts.parent_args.iter().copied().chain(std::iter::once(parts.ty.into())),"}]}
source_snippet:                 parts.parent_args.iter().copied().chain(std::iter::once(parts.ty.into())),
context_before:             args: tcx.mk_args_from_iter(
context_after:             ),