syntax_data: {"ast_node_type":"variable","tokens":[{"end":94,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let args = GenericArgs::for_item(tcx, wrapper_def_id, |param, args| match param.kind {
context_before:         let adt_def = tcx.adt_def(wrapper_def_id);
context_after:             GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => bug!(),