{"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":".map(|def_id|"}]}
                .map(|def_id| self.tcx.fn_sig(def_id).skip_binder().skip_binder())
                .type_dependent_def_id(expr.hir_id)
                .and_then(|sig| sig.inputs_and_output.split_last())