MyContainer

package com.company;

import java.util.ArrayList;
import java.util.Collections;

public class MyContainer <T extends Learner> extends ArrayList<T> implements Cloneable{
    public T min() throws EmptyContainerException{
        if(this.isEmpty()){
            throw new EmptyContainerException();
        }
        return Collections.min(this) ;
    }
    public void printContent() throws EmptyContainerException{
        if(this.isEmpty()){
            throw new EmptyContainerException();
        }
        for(T elem : this ){
            elem.printInfo();
        }
    }
    public Learner findElem(T t) throws EmptyContainerException{
        if(this.isEmpty()){
            throw new EmptyContainerException();
        }
        MyContainer<T> myContainer = (MyContainer<T>) this.clone();
        Collections.sort(myContainer);
        int index = Collections.binarySearch(myContainer, t);
        if(index>=0) {
            return myContainer.get(index);
        }
        else{
            return null;
        }
    }
    public int countSameElem(T t) throws EmptyContainerException{
        if(this.isEmpty()){
            throw new EmptyContainerException();
        }
        return Collections.frequency(this,t);
    }
}