syntax_data: {"ast_node_type":"function","tokens":[{"end":97,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn register_place(&mut self, ty: Ty<'tcx>, base: PlaceIndex, elem: TrackElem) -> PlaceIndex {
context_before:     #[tracing::instrument(level = "trace", skip(self), ret)]
context_after:         *self.projections.entry((base, elem)).or_insert_with(|| {