由于ets文件中不能使用any，无法自定义装饰器。必须要在ts文件中自定义装饰器吗？

function TestClassDecorator (target: Function) {}  
function TestMemberDecorator (target: testClass, memberName: String) {}  
function TestFunDecorator (target: testClass, propertyName: String, descriptor: PropertyDescriptor) {}  
function TestArgDecorator (target: Function, methodName: String, paramIndex: Number) {}  
  
@TestClassDecorator  
class testClass {  
  @TestMemberDecorator  
  count: number = 123;  
  
  @TestFunDecorator  
  TestFun(@TestArgDecorator param: string) {}  
}