public async Task UpdateSampleAsync_ShouldReturnOldSample()
        {
            //arrange
            Sample sample = new Sample
            {
                Id         = 1,
                SampleName = "new sample name"
            };
            ProjectDBContext projectDBContext = new ProjectDBContext(options);
            ProjectRepoDB    projectRepoDB    = new ProjectRepoDB(projectDBContext);

            //act
            var result = await projectRepoDB.UpdateSampleAsync(sample);

            //assert
            Assert.Equal(sample.SampleName, result.SampleName);
        }