Call a method that inside a nested static class from the outer class by using a trait

I have a static class, ‘Inner’, and a nested static class, ‘Deeper’, in two different classes A,B. ‘Inner’ class implements the trait C that has a method called ping(). I want to execute the method hello() (that belongs to Deeper) from the ping() method in a way that each time I’ll get either ‘Hello A’ or ‘Hello B’ according to the class that invoked the trait. This is what I wrote (I’m using katalon-studio):

public class A{  static class Inner implements C{     static class Deeper{          static void hello(){ println 'Hello A'}    }  }}public class B{  static class Inner implements C{     static class Deeper{          static void hello(){ println 'Hello B'}    }  }}public static trait C {     static void ping() {          this.Deeper.hello()     }}A.Inner.ping()B.Inner.ping()

I got the following error:

08-17-2018 04:46:57 PM - [ERROR] - Test Cases/V2/General/Draft FAILED because (of) Variable ‘Deeper’ is not defined for test case.