syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Applies a single projection element, yielding the corresponding child.
context_before: impl<'tcx> Map<'tcx> {
context_after:     pub fn apply(&self, place: PlaceIndex, elem: TrackElem) -> Option<PlaceIndex> {