syntax_data: {"ast_node_type":"variable","tokens":[{"end":56,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let type_param = generics.type_param(self, tcx);
context_before:         let generics = tcx.generics_of(item_with_generics);
context_after:         tcx.def_span(type_param.def_id)