syntax_data: {"ast_node_type":"other","tokens":[{"end":33,"kind":"keyword","start":0,"text":"impl<'tcx>"}]}
source_snippet: impl<'tcx> FmtPrinter<'_, 'tcx> {
context_before: // `region_index` and `used_region_names`.
context_after:     pub fn name_all_regions<T>(