Amazon web services 运行Dyanamo DB和创建AWS策略时出错

我已经为Dynamodb云形成模板定义了IAM策略，如下所示，我得到以下错误：

属性用户的值必须是字符串列表类型

知道我做错了什么吗

myDynamoPolicy:
   Type: AWS::IAM::Policy
   Properties: 
     PolicyDocument:
       Version: 2012-10-17
       Statement:
         Sid: AllAPIActionsOnBooks
         Effect: Allow
         Action: dynamodb:*
         Resource: 
           Ref: myDynamoDBTable
     PolicyName: DynamoDBOwnerPolicy
     Users:
        Ref: IAMUsers

---

根据AWS文档，

Users

属性必须是数组。应该是这样的：

myDynamoPolicy:
  Type: AWS::IAM::Policy
  Properties: 
    PolicyDocument:
      Version: 2012-10-17
      Statement:
        Sid: AllAPIActionsOnBooks
        Effect: Allow
        Action: dynamodb:*
        Resource: 
          Ref: myDynamoDBTable
    PolicyName: DynamoDBOwnerPolicy
    Users:
      -
        Ref: "IAMUsers"

可以找到CloudFormation模板参考