@Sendable编译报错，有什么方法解决？

// SendClass.ets 
@Sendable 
export class SendClass { 
  aaa() { 
    console.log('treeli::: i’m SendClass') 
  } 
} 
 
// TestSend.ets 
@Concurrent 
function taskFunc(sendObj: SendClass): number { 
  sendObj.aaa() 
  return 1 
} 
 
export class TestSend { 
  start() { 
    let task: taskpool.Task = new taskpool.Task(taskFunc, new SendClass()); 
    taskpool.execute(task) 
  } 
}

ERROR: ArkTS:ERROR File: /Users/didi/DevEcoStudioProjects/OkHttp/entry/src/main/ets/pages/SendClass.ets:2:2Cannot find name ‘Sendable’. 
WARN: ArkTS:WARN File: /Users/didi/DevEcoStudioProjects/OkHttp/entry/src/main/ets/pages/SendClass.ets:2:1No decorators except ArkUI decorators are currently allowed (arkts-no-decorators-except-arkui)