TestSuite suite = new TestSuite();

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {
                    return Sets.union(Sets.<String>newHashSet(), Sets.<String>newHashSet());
                  }
                })
            .named("empty U empty")
            .withFeatures(

    @Override
    protected SortedSet<Integer> create(Integer[] elements) {
      SortedSet<Integer> set = nullCheckedTreeSet(elements);
      if (set.isEmpty()) {
        /*
         * The (tooLow + 1, tooHigh) arguments below would be invalid because tooLow would be
         * greater than tooHigh.
         */
        return ContiguousSet.create(Range.openClosed(0, 1), DiscreteDomain.integers()).subSet(0, 1);
      }

    tester.testAllPublicStaticMethods(AtomicLongMap.class);
    AtomicLongMap<Object> map = AtomicLongMap.create();
    tester.testAllPublicInstanceMethods(map);
  }

  public void testCreate_map() {
    Map<String, Long> in = ImmutableMap.of("1", 1L, "2", 2L, "3", 3L);
    AtomicLongMap<String> map = AtomicLongMap.create(in);
    assertFalse(map.isEmpty());
    assertEquals(3, map.size());
    assertTrue(map.containsKey("1"));

    suite.addTest(
        SortedMultisetTestSuiteBuilder.using(
                new TestStringMultisetGenerator() {
                  @Override
                  protected Multiset<String> create(String[] elements) {
                    return TreeMultiset.create(Arrays.asList(elements));
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {

                new TestStringSetMultimapGenerator() {
                  @Override
                  protected SetMultimap<String, String> create(Entry<String, String>[] entries) {
                    SetMultimap<String, String> multimap = LinkedHashMultimap.create();
                    for (Entry<String, String> entry : entries) {
                      multimap.put(entry.getKey(), entry.getValue());
                    }

     *
     * @see ArtifactCoordinateFactory#create(Session, String)
     */
    @Override
    public ArtifactCoordinate createArtifactCoordinate(String coordString) {
        return getService(ArtifactCoordinateFactory.class).create(this, coordString);
    }

    /**
     * Shortcut for <code>getService(CoordinateFactory.class).create(...)</code>
     *

!!! tip
    You would do the same for any other Peewee database, including `PostgresqlDatabase`, `MySQLDatabase`, etc.

## Create the database models

Let's now see the file `sql_app/models.py`.

### Create Peewee models for our data

Now create the Peewee models (classes) for `User` and `Item`.

        .addEqualityGroup(
            MediaType.create("text", "plain").withParameter("a", "value"),
            MediaType.create("text", "plain").withParameter("A", "value"))
        .addEqualityGroup(
            MediaType.create("text", "plain").withParameter("a", "VALUE"),
            MediaType.create("text", "plain").withParameter("A", "VALUE"))
        .addEqualityGroup(
            MediaType.create("text", "plain")

        .addEqualityGroup(
            MediaType.create("text", "plain").withParameter("a", "value"),
            MediaType.create("text", "plain").withParameter("A", "value"))
        .addEqualityGroup(
            MediaType.create("text", "plain").withParameter("a", "VALUE"),
            MediaType.create("text", "plain").withParameter("A", "VALUE"))
        .addEqualityGroup(
            MediaType.create("text", "plain")

    return suite;
  }

  protected LinkedListMultimap<String, Integer> create() {
    return LinkedListMultimap.create();
  }

  /** Confirm that get() returns a List that doesn't implement RandomAccess. */
  public void testGetRandomAccess() {
    Multimap<String, Integer> multimap = create();
    multimap.put("foo", 1);
    multimap.put("foo", 3);