`path_segments` returns `None` for `s3://bucket`

[Kinrany]

The docs for Url::path_segments state:

Unless this URL is cannot-be-a-base, return an iterator of ‘/’ slash-separated path segments, each as a percent-encoded ASCII string.

Return None for cannot-be-a-base URLs.

When Some is returned, the iterator always contains at least one string (which may be empty).

However for a URL like s3://bucket the method returns None despite the URL not being a cannot-be-a-base according to the value's debug representation:

Url { scheme: "s3", cannot_be_a_base: false, username: "", password: None, host: Some(Domain("bucket")), port: None, path: "", query: None, fragment: None }