syntax_data: {"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"candidate:"}]}
source_snippet:         candidate: SelectionCandidate<'tcx>,
context_before:         obligation: &PolyTraitObligation<'tcx>,
context_after:     ) -> Result<Selection<'tcx>, SelectionError<'tcx>> {