syntax_data: {"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"None"}]}
source_snippet:                     None | Some(Err(SelectionError::Overflow(OverflowError::Canonical))) => {}
context_before:                 match infcx.selection_cache.get(&(param_env, pred), tcx) {
context_after:                     res => bug!("unexpected local cache result: {res:?}"),