anchor.diff:  import "Block.dart";
  +import 'dart:math';
  +
   class Level
   {
     List<String> _colors;
  
positive.code:   List<List<Block>> _startField;
    int _levelTimeSec;
    int _comboHoldTime;
    double _requiredScore;
  
    Level()
    {
  
    }
  
    List<String> getColors ()
    {
  
negative.code:     return _comboHoldTime;
    }
  
    int getRequiredScore()
    {
      return _requiredScore;
    }
  
    /**
     * #####################################################################################
     *
     * Convert for JSON Methods
     *
     * #####################################################################################
     */
  
    static List<List<Block>> convertStartfieldMapToStartField(List<List<Map>> mapStartField)
    {
     List<List<Block>> field = new List<List<Block>>();
  
     for(int y = 0; y < mapStartField.length; y++)
     {
        field.add(new List<Block>());
        for(int x = 0; x < mapStartField[0].length; x++)
        {
          field[y].add(new Block(mapStartField[x][y]["_color"],new Point(mapStartField[x][y]["_PosX"],mapStartField[x][y]["_PosY"])));
        }
     }
  
      return field;
    }
  
    Map convertLevelToMap()
    {
      Map retMap = new Map();
      List<List<Map>> convertedField = new List<List<Map>>();
  
      for(int y = 0; y < 4;y++)
      {
        convertedField.add(new List<Map>());
  
        for(int x = 0; x < 3; x++)
        {
          convertedField[y].add(_startField[y][x].convertBlock());
        }
      }
  
      retMap["_levelNum"] = _levelNum;
      retMap["_levelTimeSec"] = _levelTimeSec;
      retMap["_comboHoldTime"] = _comboHoldTime;
      retMap["_requiredScore"] = _requiredScore;
      retMap["_colors"] = _colors;
      retMap["_blocks"] = _blocks;
      retMap["_startField"] = convertedField;
  
      return retMap;
    }
  
    String toString()
    {
      String ret;
  
      ret = "Level: " + _levelNum.toString() +
          "\nLevel Time: " + _levelTimeSec.toString() +
          " s\nRequired Points: " + _requiredScore.toString() +
          "\nCombo Hold Time: " + _comboHoldTime.toString() +
          " s\nAllowed Colors: " + _colors.toString() +
          "\nAllowed Block Types: " + _blocks.toString() +
          "\nField Y: " + _startField.length.toString() +
          "\nField X: " + _startField[0].length.toString() + "\n";
      return ret;
    }
  }