* returned URI may be semantically different from this URL:
   *
   *  * Characters forbidden by URI like `[` and `|` will be escaped.
   *
   *  * Invalid percent-encoded sequences like `%xx` will be encoded like `%25xx`.
   *
   *  * Whitespace and control characters in the fragment will be stripped.
   *
   * These differences may have a significant consequence when the URI is interpreted by a