How to use the pystac.Catalog function in pystac

def test_full_copy_1(self):
        with TemporaryDirectory() as tmp_dir:
            cat = Catalog(id='test', description='test catalog')

            item = Item(id='test_item',
                        geometry=RANDOM_GEOM,
                        bbox=RANDOM_BBOX,
                        datetime=datetime.utcnow(),
                        properties={})

            cat.add_item(item)

            cat.normalize_hrefs(os.path.join(tmp_dir, 'catalog-full-copy-1-source'))
            cat2 = cat.full_copy()
            cat2.normalize_hrefs(os.path.join(tmp_dir, 'catalog-full-copy-1-dest'))

            self.check_catalog(cat, 'source')
            self.check_catalog(cat2, 'dest')

def test_map_items_multiple_2(self):
        catalog = Catalog(id='test-1', description='Test1')
        item1 = Item(id='item1',
                     geometry=RANDOM_GEOM,
                     bbox=RANDOM_BBOX,
                     datetime=datetime.utcnow(),
                     properties={})
        item1.add_asset('ortho', Asset(href='/some/ortho.tif'))
        catalog.add_item(item1)
        kitten = Catalog(id='test-kitten', description='A cuter version of catalog')
        catalog.add_child(kitten)
        item2 = Item(id='item2',
                     geometry=RANDOM_GEOM,
                     bbox=RANDOM_BBOX,
                     datetime=datetime.utcnow(),
                     properties={})
        item2.add_asset('ortho', Asset(href='/some/other/ortho.tif'))
        kitten.add_item(item2)

        def modify_item_title(item):
            item.title = 'Some new title'
            return item

        def create_label_item(item):
            # Assumes the GEOJSON labels are in the
            # same location as the image

def test_clear_items_removes_from_cache(self):
        catalog = Catalog(id='test', description='test')
        subcat = Catalog(id='subcat', description='test')
        catalog.add_child(subcat)
        item = Item(id='test-item',
                    geometry=RANDOM_GEOM,
                    bbox=RANDOM_BBOX,
                    datetime=datetime.utcnow(),
                    properties={'key': 'one'})
        subcat.add_item(item)

        items = list(catalog.get_all_items())
        self.assertEqual(len(items), 1)
        self.assertEqual(items[0].properties['key'], 'one')

        subcat.clear_items()
        item = Item(id='test-item',
                    geometry=RANDOM_GEOM,
                    bbox=RANDOM_BBOX,

def test_can_add_custom_extension(self):
        prev_extensions = pystac.STAC_EXTENSIONS.get_registered_extensions()

        pystac.STAC_EXTENSIONS.add_extension(
            ExtensionDefinition("test", [
                ExtendedObject(Catalog, TestCatalogExt),
                ExtendedObject(Collection, TestCollectionExt),
                ExtendedObject(Item, TestItemExt)
            ]))

        try:
            cat = TestCases.test_case_2()
            col = cat.get_child('1a8c1632-fa91-4a62-b33e-3a87c2ebdf16')
            item = next(cat.get_all_items())

            cat.ext.enable("test")
            col.ext.enable("test")
            item.ext.enable("test")

            self.assertEqual(cat.ext.test.test_id, cat.id)
            self.assertEqual(col.ext.test.xmin, col.extent.spatial.bboxes[0][0])
            self.assertEqual(item.ext.test.asset_keys, set(item.assets))

def test_case_3():
        root_cat = Catalog(id='test3',
                           description='test case 3 catalog',
                           title='test case 3 title')

        image_item = Item(id='imagery-item',
                          geometry=RANDOM_GEOM,
                          bbox=RANDOM_BBOX,
                          datetime=datetime.utcnow(),
                          properties={})

        image_item.add_asset(
            'ortho',
            Asset(href='some/geotiff.tiff', media_type=MediaType.GEOTIFF))

        overviews = [
            LabelOverview('label',
                          counts=[LabelCount('one', 1),

catalog.add_child(subcat)

        children = list(catalog.get_children())
        self.assertEqual(len(children), 1)
        self.assertEqual(children[0].description, 'test')

        catalog.clear_children()
        subcat = Catalog(id='subcat', description='test2')
        catalog.add_child(subcat)

        children = list(catalog.get_children())
        self.assertEqual(len(children), 1)
        self.assertEqual(children[0].description, 'test2')

        catalog.remove_child('subcat')
        subcat = Catalog(id='subcat', description='test3')
        catalog.add_child(subcat)

        children = list(catalog.get_children())
        self.assertEqual(len(children), 1)
        self.assertEqual(children[0].description, 'test3')

def test_clear_items_removes_from_cache(self):
        catalog = Catalog(id='test', description='test')
        subcat = Catalog(id='subcat', description='test')
        catalog.add_child(subcat)
        item = Item(id='test-item',
                    geometry=RANDOM_GEOM,
                    bbox=RANDOM_BBOX,
                    datetime=datetime.utcnow(),
                    properties={'key': 'one'})
        subcat.add_item(item)

        items = list(catalog.get_all_items())
        self.assertEqual(len(items), 1)
        self.assertEqual(items[0].properties['key'], 'one')

        subcat.clear_items()
        item = Item(id='test-item',
                    geometry=RANDOM_GEOM,

Note: This is used internally in STAC_IO to deserialize STAC Objects.
    It is in the top level __init__ in order to avoid circular dependencies.
    """
    if identify_stac_object_type(d) == STACObjectType.ITEM:
        collection_cache = None
        if root is not None:
            collection_cache = root._resolved_objects.as_collection_cache()

        merge_common_properties(d, json_href=href, collection_cache=collection_cache)

    info = identify_stac_object(d)

    d = migrate_to_latest(d, info)

    if info.object_type == STACObjectType.CATALOG:
        return Catalog.from_dict(d, href=href, root=root)

    if info.object_type == STACObjectType.COLLECTION:
        return Collection.from_dict(d, href=href, root=root)

    if info.object_type == STACObjectType.ITEMCOLLECTION:
        if Extension.SINGLE_FILE_STAC in info.common_extensions:
            return SingleFileSTAC.from_dict(d)

        return ItemCollection.from_dict(d)

    if info.object_type == STACObjectType.ITEM:
        if Extension.EO in info.common_extensions:
            return EOItem.from_dict(d, href=href, root=root)

        if Extension.LABEL in info.common_extensions:
            return LabelItem.from_dict(d, href=href, root=root)