anchor.diff:        }
         return BigInt.from(other).toUnsigned(_width) == _bigIntValue;
       } else if (other is BigInt && !other.isNegative) {
  -      if (_bigIntValue != null) {
  -        return _bigIntValue == other;
  -      }
  -      return BigInt.from(_intValue).toUnsigned(_width) == other;
  +      return toBigInt() == other;
       }
       return false;
     }
  
positive.code:   String toRadixString(int radix) => _intValue != null
        ? _intValue.toRadixString(radix)
        : _bigIntValue.toRadixString(radix);
  }
  
  /// Ultimate sink that stores the final CRC value.
  
negative.code: import 'dart:convert' show ByteConversionSinkBase;
  
  /// Represents a CRC value. Objects of this class should only be tested for
  /// equality against [int] or [BigInt], printed with [toString] or
  /// [toRadixString], or up-valued [toBigInt].
  class CrcValue {
    final int _intValue;
    final BigInt _bigIntValue;
  