solid-blog

8.java

public interface Everything { run() } 
// similar to Object class(root class, it has most generalized methods) in Java 

public class HumanoidRobot extends Everything { 
    public void run() { 
        // code to run using batteries.
    }
}
public class Human extends Everything {
    public void run() { 
        // code to run using physical streangth.
    }
}

// Example:
    Everything ev = new HumanoidRobot()
    Everything ev = new Human()
// if you apply the substition rule it satisfies, since both does the run operation but differently.