anchor.diff:    /// of [uri], and only the substring from `start` to `end` is parsed as a URI.
     ///
     /// Returns `null` if the [uri] string is not valid as a URI or URI reference.
  +  ///
  +  /// Example:
  +  /// ```dart
  +  /// final uri = Uri.tryParse(
  +  ///     'https://dart.dev/guides/libraries/library-tour#utility-classes', 0,
  +  ///     16);
  +  /// print(uri); // https://dart.dev
  +  ///
  +  /// var notUri = Uri.tryParse('::Not valid URI::');
  +  /// print(notUri); // null
  +  /// ```
     static Uri? tryParse(String uri, [int start = 0, int? end]) {
       // TODO: Optimize to avoid throwing-and-recatching.
       try {
  
positive.code:   /// A normalized path does not contain `.` segments or non-leading `..`
    /// segments.
    /// Only a relative path with no scheme or authority may contain
    /// leading `..` segments,
    /// a path that starts with `/` will also drop any leading `..` segments.
    ///
    /// This uses the same normalization strategy as `Uri().resolve(this)`.
  
negative.code:   /// If [plusToSpace] is `true`, plus characters will be converted to spaces.
    ///
    /// The decoder will create a byte-list of the percent-encoded parts, and then
    /// decode the byte-list using [encoding]. The default encoding is UTF-8.
    static String _uriDecode(
        String text, int start, int end, Encoding encoding, bool plusToSpace) {
      assert(0 <= start);
  