syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"Err(SelectionError::Overflow(OverflowError::Canonical))"}]}
source_snippet:             Err(SelectionError::Overflow(OverflowError::Canonical)) => {
context_before:         match self.confirm_candidate(obligation, candidate) {
context_after:                 assert!(self.query_mode == TraitQueryMode::Canonical);