public void CreateAsync_ShouldAddUser()
{
User user = new User();
_dataRepositoryMock.Setup(f => f.OnPostAsync <User>(It.IsAny <string>(), user, It.IsAny <string>()))
.Returns(Task.FromResult(user));
User addedUser = _sut.CreateAsync(user).Result;
Assert.That(addedUser, Is.EqualTo(user));
_dataRepositoryMock.Verify(f => f.OnPostAsync(It.IsAny <string>(), user, It.IsAny <string>()), Times.Once());
}