syntax_data: {"ast_node_type":"variable","tokens":[{"end":59,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let generics = tcx.generics_of(item_with_generics);
context_before:     pub fn span_from_generics(self, tcx: TyCtxt<'tcx>, item_with_generics: DefId) -> Span {
context_after:         let type_param = generics.type_param(self, tcx);