I have a method let's say in `ClassA`. I want to pass a method from `ClassB` as an argument to that method in `ClassA`. In this case I want to pass the `getCode` method from `ClassB`. I don't have any instance of `ClassB` and I'd like to achieve this without having to create one.

I've tried using simple method reference, but it does not work this way.
I don't want to make getCode a static method either.

```
public class ClassA {

   public void validate() {
       Validation validation = new Validation(ClassB::getCode, code);
       //...
   }

}

```

My final goal is to have a RequestValidator class to which add validations, each validation will be created with a specific method and a string in its constructor, in this case getCode from classB and code. Please note I only want one instance of RequestValidator. Something like this:

```
RequestValidator validator = new RequestValidator<>()
        .addValidation(new Validation(ClassB::getCode, code))
        .addValidation(new Validation(ClassB::getName, name));

```