syntax_data: {"ast_node_type":"other","tokens":[{"end":65,"kind":"keyword","start":0,"text":"data:"}]}
source_snippet:         data: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
context_before:         ty: Ty<'tcx>,
context_after:         region: ty::Region<'tcx>,