What is the name of this coding style or pattern?

Sorry for ambiguous question subject, But I don't know the more proper title.

Anyway, I found a kind of style. It can be handy when you have to code rebase.
Here is a example, written by JAVA.

original code

/**
org/open/source
├── Foo.java
└── Bar.java
*/
// in Foo.java
package org.open.source;
public class Foo {
    private somePrivate="kenel memory";
    ...
    private void doSomethingWithSecret() {
        system.out.println(this.somePrivate);
    }
    public void doIt() {
        system.out.println("call Do it");
        this.doSomethingWithSecret();
    }
}

// in Bar.java

package org.open.source;

public class Bar {
    private Foo foo;
    public static void main(String args[]) {
        ...
        foo.doIt();
    }        
}
// Result:
// call Do it
// kenel memory

modified code

/**
org/open/source
├── patched
|   └── Foo.java
├── Foo.java
└── Bar.java
*/
// in Foo.java
package org.open.source;
public class Foo { // covert all private keyword to protected.
    pretected somePrivate="kenel memory";
    ...
    protected void doSomethingWithSecret() {
        system.out.println(this.somePrivate);
    }
    public void doIt() {
        system.out.println("call Do it");
        this.doSomethingWithSecret();
    }
}

// in patched/Foo.java
public Foo extends org.open.source.Foo {
    @Override
    protected void doSomethingWithSecret() {
        system.out.println("intel meltdown it");
    }
};

// in Bar.java

package org.open.source;
import org.open.source.patched.Foo; // add import statement.

public class Bar {
    private Foo foo;
    public static void main(String args[]) {
        ...
        foo.doIt();
    }        
} // note that no code change except import statement.
// Result:
// call Do it
// intell meltdown it

PROS:
If you code like this, you can easily rebase the code when open source owner commits code. the conflicted code can be distinguished 2 types, one is "import statement", the other is "private-protected keyword".

CONS: If you in trouble after code rebase. And you don't have concrete unit test. it is very hard to find where is wrong.

I think someone finds this trick before me. this trick should have its name. What is it?