})
		expectErr := (err != nil)

		if expectErr != testCase.expectErr {
			t.Fatalf("case %v: error: expected: %v, got: %v", i+1, testCase.expectErr, expectErr)
		}
	}
}

func testStorageAPIRenameFile(t *testing.T, storage StorageAPI) {
	err := storage.AppendFile(context.Background(), "foo", "myobject", []byte("foo"))
	if err != nil {
		t.Fatalf("unexpected error %v", err)
	}