anchor.diff:      "isNullable": "(",
       "location": ")",
       "parts": "?",
  -    "extension": "_"
  +    "extension": "_",
  +    "multiple assignment": "~"
     };
   
     static String demap(String key) {
  
positive.code:       return {
          "type": "return",
          "value": statement.expression != null ? _generateExpression(statement.expression) : null
        };
      } else if (statement is BreakStatement) {
        return {
  
negative.code:         _buildExpression(it["value"]),
          new Block(it["block"].map(_buildStatement).toList())
        );
      } else if (type == "multiple assignment") {
        return new MultiAssignment(it["ids"], _buildExpression(it["value"]), it["immutable"], it["isInitialDefine"], it["isNullable"]);
      } else if (type == "type") {
        return new TypeBlock(
          it["name"],
  