//闭包中定义一个闭包
def nestClouser = {
    def innerClouser = {
         //this 代表闭包定义处的类
        println "innerClouser this:" + this
         //owner 代表闭包定义处的类或对象
        println "innerClouser owner:" + owner
        //delegate 代表任意第三方对象 默认值=owner
        println "innerClouser delegate:" + delegate
    }
	//innerClouser.delegate = p //修改默认的delegate，this和owner不能修改
    innerClouser.call()
}
nestClouser.call()
out:
innerClouser this:Demo49@3ecedf21 
innerClouser owner:Demo49$_run_closure2@6df20ade //指向了它最近的一个类或对象
innerClouser delegate:Demo49$_run_closure2@6df20ade
//innerClouser delegate:Person@9a7a808

class Student{
    String name
    def pretty = {"my name is ${name}"}
    String toString(){
        pretty.call()
    }
}
class Teacher{
    String name
}
def stu = new Student(name: 'wcq')
def tea = new Teacher(name: 'qqq')
stu.pretty.delegate = tea
stu.pretty.resolveStrategy = Closure.DELEGATE_FIRST
println  stu.toString()