anchor.diff:    const Utf8Codec({bool allowMalformed = false})
         : _allowMalformed = allowMalformed;
   
  -  /// The name of this codec, "utf-8".
  +  /// The name of this codec is "utf-8".
     String get name => "utf-8";
   
     /// Decodes the UTF-8 [codeUnits] (a list of unsigned 8-bit integers) to the
  
positive.code:   /// writes it to [_buffer].
    ///
    /// Returns true if the [nextCodeUnit] was combined with the
    /// [leadingSurrogate]. If it wasn't then nextCodeUnit was not a trailing
    /// surrogate and has not been written yet.
    ///
    /// It is safe to pass 0 for [nextCodeUnit] in which case a replacement
    /// character is written to represent the unpaired lead surrogate.
    bool _writeSurrogate(int leadingSurrogate, int nextCodeUnit) {
      if (_isTailSurrogate(nextCodeUnit)) {
  
negative.code:   /// If the [codeUnits] start with the encoding of a
    /// [unicodeBomCharacterRune], that character is discarded.
    ///
    /// If [allowMalformed] is `true`, the decoder replaces invalid (or
    /// unterminated) character sequences with the Unicode Replacement character
    /// `U+FFFD` (�). Otherwise it throws a [FormatException].
    ///
  