url(relativeTo:)
Returns a URL based on the component settings and relative to a given base URL.
Declaration
func url(relativeTo base: URL?) -> URL?Discussion
If the NSURLComponents has an authority component (user, password, host or port) and a path component, then the path must either begin with “/” or be an empty string. If the NSURLComponents does not have an authority component (user, password, host or port) and has a path component, the path component must not start with “//”. If those requirements are not met, nil is returned.