Also, you think there are zero restrictions on what can be included and enforced in a rental lease?
Put it this way...There is no law that states a plumber cannot contractually charge $50,000 to change a toilet. Yet if you refuse to pay it upon completion, and he sues you for it in court, why would the judge throw it out? Hint: Please apply your knowledge of "contract law."
.....And off to Google he goes.