syntax_data: {"ast_node_type":"variable","tokens":[{"end":95,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let (self_ty, impl_trait_ref) = if tcx.generics_of(impl_def_id).count() <= args.len() {
context_before:         let impl_trait_ref = tcx.impl_trait_ref(impl_def_id);
context_after:             (