syntax_data: {"ast_node_type":"other","tokens":[{"end":13,"kind":"keyword","start":0,"text":"}"}]}
source_snippet:             }
context_before:                 infcx.instantiate_ty_var_raw(self, true, a_vid, self.ambient_variance, b)?;
context_after:             (_, ty::Infer(ty::TyVar(b_vid))) => {