// The chain of responsibility pattern has a

// group of objects that are expected to between

// them be able to solve a problem.

// If the first Object can't solve it, it passes

// the data to the next Object in the chain

public interface Chain {

// Defines the next Object to receive the data

// if this Object can't process it

public void setNextChain(Chain nextChain);

// Either solves the problem or passes the data

// to the next Object in the chain

public void calculate(Numbers request);

}