syntax_data: {"ast_node_type":"function","tokens":[{"end":76,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:                 fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
context_before:             impl<I: Interner> fmt::Debug for $ty<I> {
context_after:                     <I as IrPrint<$ty<I>>>::print_debug(self, fmt)