message: Add operator property in UnaryOperand class,
diff: @@ -123,6 +123,9 @@ export class UnaryOperand extends Operand {
  OperandMaker.throwInvalidOperatorError(operatorName);
  }
  }
  + public get operator(): string {
  + return this.operatorName;
  + }
  public getType(): string {
  return "unary";
  }
  