syntax_data: {"ast_node_type":"function","tokens":[{"end":44,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn thir(&self) -> &'a thir::Thir<'tcx> {
context_before: impl<'a, 'tcx> visit::Visitor<'a, 'tcx> for IsThirPolymorphic<'a, 'tcx> {
context_after:         self.thir