anchor.diff:        return false;
       }
       // Work out what the first latitude character indicates for latitude.
  -    var firstLatValue = decode_[code.codeUnitAt(0)] * ENCODING_BASE;
  +    var firstLatValue = _decode[code.codeUnitAt(0)] * ENCODING_BASE;
       if (firstLatValue >= LATITUDE_MAX * 2) {
         // The code would decode to a latitude of >= 90 degrees.
         return false;
       }
       if (code.length > 1) {
         // Work out what the first longitude character indicates for longitude.
  -      var firstLngValue = decode_[code.codeUnitAt(1)] * ENCODING_BASE;
  +      var firstLngValue = _decode[code.codeUnitAt(1)] * ENCODING_BASE;
         if (firstLngValue >= LONGITUDE_MAX * 2) {
           // The code would decode to a longitude of >= 180 degrees.
           return false;
  
positive.code: 
      // Check code contains only valid characters.
      for (int ch in code.codeUnits) {
        if (ch > decode_.length || decode_[ch] < -1) {
          return false;
        }
      }
  
negative.code:     var lngPlaceValue = GRID_SIZE_DEGREES;
      var i = 0;
      while (i < code.length) {
        var codeIndex = _decode[code.codeUnitAt(i)];
        var row = (codeIndex / GRID_COLUMNS).floor();
        var col = codeIndex % GRID_COLUMNS;
  
  