and class else false for fun if nil or return super this true var while

// expect: AND and null
// expect: CLASS class null
// expect: ELSE else null
// expect: FALSE false null
// expect: FOR for null
// expect: FUN fun null
// expect: IF if null
// expect: NIL nil null
// expect: OR or null
// expect: RETURN return null
// expect: SUPER super null
// expect: THIS this null
// expect: TRUE true null
// expect: VAR var null
// expect: WHILE while null
// expect: EOF  null