public async Task AddLeft_Should_ReturnAccepted_When_ValidInput()
{
var guid = Guid.NewGuid();
var input = Convert.ToBase64String(Encoding.UTF8.GetBytes("TestString"));
var result = await _diffController.AddRight(guid, input) as AcceptedResult;
Assert.IsNotNull(result);
Assert.AreEqual(202, result.StatusCode);
}