Unmodifiable list, set and collection if Java

CollectionsTest.java

package com.ffbit.collections;

import static org.hamcrest.CoreMatchers.hasItems;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.not;
import static org.junit.Assert.assertThat;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

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

public class CollectionsTest {
    private List<Integer> list;
    private Set<Integer> set;
    private Collection<Integer> collection;

    @Before
    public void setUp() {
        list = new ArrayList<Integer>();
        set = new HashSet<Integer>();
        collection = new LinkedList<Integer>();
    }

    @Test
    public void unmodifiableListShouldBeEqualToModifiedOriginOne() {
        List<Integer> unmodifiable = Collections.unmodifiableList(list);
        list.add(1);

        assertThat(unmodifiable, is(list));
    }

    @Test
    public void unmodifiableSetShouldBeEqualToModifiedOriginOne() {
        Set<Integer> unmodifiable = Collections.unmodifiableSet(set);
        set.add(1);

        assertThat(unmodifiable, is(set));
    }

    @Test
    public void unmodifiableCollectionShouldBeEqualToModifiedOriginOne() {
        Collection<Integer> unmodifiable = Collections
                .unmodifiableCollection(collection);
        collection.add(1);

        // java.util.Collections.UnmodifiableCollection does not override the
        // java.lang.Object.equals(Object o) method.
        assertThat(unmodifiable, is(not(collection)));

        assertThat(unmodifiable, hasItems(collection.toArray(new Integer[] {})));
    }

}