syntax_data: {"ast_node_type":"function","tokens":[{"end":64,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
context_before: {
context_after:         <I as IrPrint<OutlivesPredicate<I, T>>>::print(self, fmt)