syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":")"}]}
source_snippet:     ) -> Result<EvaluationResult, OverflowError> {
context_before:         op: impl FnOnce(&mut Self) -> Result<EvaluationResult, OverflowError>,
context_after:         self.infcx.probe(|snapshot| -> Result<EvaluationResult, OverflowError> {