/* syntax:
 public func preconditionFailure(
                _ message: @autoclosure () -> String = default,
                file: StaticString = #file,
                line: UInt = #line) -> Never
*/
func validateAge(age: Int) -> Bool {
        guard age >= 3 else {
            preconditionFailure("Age can't be less than 3")
        }
        return true
    }

_ = validateAge(age: 2)