syntax_data: {"ast_node_type":"function","tokens":[{"end":97,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn into_diag_arg(self, path: &mut Option<std::path::PathBuf>) -> rustc_errors::DiagArgValue {
context_before: impl<'tcx> rustc_errors::IntoDiagArg for TraitRefPrintSugared<'tcx> {
context_after:         ty::tls::with(|tcx| {