JUnit Tests that show fixed-size list is unmutable and add, remove, clear methods throw UnsupportedOperationException

arraysaslist.java

package org.mshowto;

import org.junit.Before;
import org.junit.Test;

import java.util.Arrays;
import java.util.List;
import java.util.stream.IntStream;

public class arraysaslist {

    private Integer[] numbers;

    @Before
    public void initArray() {
        // 1. create a sample numbers array
        numbers = new Integer[100];
        IntStream.range(0, 100).forEach((elem) -> {
            numbers[elem] = elem;
        });
    }

    @Test(expected = UnsupportedOperationException.class)
    public void testAdd() {

        // 1. convert the array to fixed-size list
        List<Integer> numbersFixedSizeList = Arrays.asList(numbers);
        // invoke add method (UnsupportedOperationException shall be thrown)
        numbersFixedSizeList.add(578);
    }

    @Test(expected = UnsupportedOperationException.class)
    public void testRemove() {

        // 1. convert the array to fixed-size list
        List<Integer> numbersFixedSizeList = Arrays.asList(numbers);
        // invoke remove method (UnsupportedOperationException shall be thrown)
        numbersFixedSizeList.remove(0);
    }

    @Test(expected = UnsupportedOperationException.class)
    public void testClear() {

        // 1. convert the array to fixed-size list
        List<Integer> numbersFixedSizeList = Arrays.asList(numbers);
        // invoke clear method (UnsupportedOperationException shall be thrown)
        numbersFixedSizeList.clear();
    }

}