A zoning ordinance of the city of Dallas, Texas, prohibited the use of property in a residential district for gasoline filling stations. Lombardo brought an action against the city to test the validity of the ordinance. He contended that the ordinance violated v the rights of the owners of property in such districts. Do you agree with this contention? [Lombardo v. City of Dallas, 73 S.W.2d 475 (Tex.)]