}

    def "'#relativePath' fromChild '#child' is '#result'"() {
        expect:
        VfsRelativePath.of(relativePath).pathFromChild(child).asString == result
        VfsRelativePath.of(child).pathToChild(relativePath) == result

        where:
        relativePath | child | result
        "a/b"        | "a"   | "b"
        "a/b"        | ""    | "a/b"
        ""           | ""    | ""
    }

     *
     * E.g.
     *   (some, some/path) -> path
     *   (some, some/path/othere) -> path/other
     *   (C:, '') -> C:
     */
    public String pathToChild(String relativeChildPath) {
        return isEmpty()
            ? relativeChildPath
            : relativeChildPath.substring(length() + 1);
    }

    /**