+ (id)rentalPropertyOfType:(PropertyType)newPropertyType
                rentingFor:(float)newRentalPrice
                 atAddress:(NSString *)newAddress
{
   id newObject = [[CTRentalProperty alloc] initWithAddress:newAddress
                                                rentalPrice:newRentalPrice
                                                    andType:newPropertyType];
   return [newObject autorelease];
}
