以下代码在代码“cfnsecuritygroupingres sgi=（cfnsecuritygroupingres）obj”行生成“software.amazon.jsii.jsiobject cannot be cast to software.amazon.awscdk.services.ec2.cfnsecuritygroupingres”错误

CfnSecurityGroup cfnSecurityGroup = (CfnSecurityGroup) resource_SecurityGroup.getCfnresource();

    if (cfnSecurityGroup.getSecurityGroupIngress() != null) {

      List<CfnSecurityGroupIngress> cfnSecurityGroupIngress = (List<CfnSecurityGroupIngress>) cfnSecurityGroup.getSecurityGroupIngress();

      ListIterator<CfnSecurityGroupIngress> it = cfnSecurityGroupIngress.listIterator();
      while (it.hasNext()) {
        Object obj = it.next();
        LOG.debug("obj: " + obj.toString());
        CfnSecurityGroupIngress sgi = (CfnSecurityGroupIngress)obj;
        LOG.debug("getFromPort" + sgi.getFromPort());
      }

如何访问securitygroupingress属性？
注意，我已经确定cfnsecuritygroup.ingresproperty是cfnsecuritygroupingres.lisiterator（）中存在的接口类型。不过，我不知道该怎么办。
Maven

<dependency>
        <groupId>software.amazon.awscdk</groupId>
        <artifactId>cdk-cloudformation-include</artifactId>
        <version>1.79.0</version>
    </dependency>

敬孔戴