syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"iter::once(impl_.self_ty.span).chain(trait_args).chain(dummy_spans_for_default_args)"}]}
source_snippet:         iter::once(impl_.self_ty.span).chain(trait_args).chain(dummy_spans_for_default_args)
context_before:             impl_.of_trait.into_iter().flat_map(|trait_ref| iter::repeat(trait_ref.path.span));
context_after:     } else {