assertNoneType(new NPlaceHolder());
assertNoneType(new NPrint(null, null));
assertNoneType(new NQname(null, new NName("")));
assertNoneType(new NRaise(null, null, null));
assertNoneType(new NRepr(null));
assertNoneType(new NReturn(null));
assertNoneType(new NSlice(null, null, null));
assertNoneType(new NStr());
assertNoneType(new NSubscript(null, null));
assertNoneType(new NTryExcept(null, null, null));
assertNoneType(new NTryFinally(null, null));