syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"ty::Closure(_,"}]}
source_snippet:         ty::Closure(_, args) => args.as_closure().sig().c_variadic(),
context_before:         ty::FnDef(..) => tcx.fn_sig(def_id).instantiate_identity().c_variadic(),
context_after:         _ => false,