使用Groovy读取特定yaml值

我有这个yaml配置文件：

environmentMapping:
 ci-develop:
   inner: ABCD-npr-XA
   outer: ABCD-npr-XB
   outer-public: ABCD-npr-XC
   frontend: ABCD-npr-XD
 dev-develop:
   inner: BCDE-npr-ZA
   outer: BCDE-npr-ZB
   outer-public: BCDE-npr-ZC
   frontend: BCDE-npr-ZD 

我想知道如何访问特定值

这是我的密码：

  configs = readYaml file: 'configs.yaml'
  def env = 'ci-develop'
  def zone = 'inner'
  echo configs.environmentMapping.${env}.${zone}

这是行不通的

如何获取ci develop->Internal的值

configs = readYaml file: 'configs.yaml'
def env = 'ci-develop'
def zone = 'inner'

echo configs.environmentMapping[env][zone]