def METHOD_NAME(self):
    """ Test get_library_keys() """
    libraries = [LibraryFactory.create(modulestore=self.store) for _ in range(3)]
    lib_keys_expected = {lib.location.library_key for lib in libraries}
    lib_keys_actual = set(self.store.get_library_keys())
    assert lib_keys_expected == lib_keys_actual