'Checks that available_tags list is not empty'

def test_aside_contains_tags(self):

    sids = ScopeIds(user_id='bob', block_type='bobs-type', def_id='definition-id', usage_id='usage-id')
    key_store = DictKeyValueStore()
    field_data = KvsFieldData(key_store)
    runtime = TestRuntime(services={'field-data': field_data})
    xblock_aside = StructuredTagsAside(scope_ids=sids, runtime=runtime)
    available_tags = xblock_aside.get_available_tags()
    self.assertEquals(len(available_tags), 2, 'StructuredTagsAside    should    contains    two    tag    categories')
