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