public async Task AddEntityWithConflict()
        {
            // Arrange
            const long longValue = 555;
            const string stringValue = "555";
            var entity = new Poco
            {
                LongValue = longValue,
                StringValue = stringValue
            };

            await _repository.AddAsync(entity);
            Exception exception = null;

            // Act
            try
            {
                await _repository.AddAsync(entity);
            }
            catch (Exception e)
            {
                exception = e;
            }

            // Assert
            Assert.NotNull(exception);
            Assert.IsType<ConflictException>(exception);
        }
        public async Task AddEntity()
        {
            // Arrange
            const long longValue = 555;
            const string stringValue = "555";
            var entity = new Poco
            {
                LongValue = longValue,
                StringValue = stringValue
            };

            // Act
            Poco result = await _repository.AddAsync(entity);

            // Assert
            Assert.Equal(longValue, result.LongValue);
            Assert.Equal(stringValue, result.StringValue);
            Assert.NotEqual(null, result.Id);
        }
        public async Task DeleteEntityWithNotFound()
        {
            // Arrange
            const long longValue = 555;
            const string stringValue = "555";

            var entity = new Poco
            {
                LongValue = longValue,
                StringValue = stringValue
            };

            Exception exception = null;

            // Act
            try
            {
                await _repository.DeleteAsync(entity);
            }
            catch (Exception e)
            {
                exception = e;
            }

            // Assert
            Assert.NotNull(exception);
            Assert.IsType<NotFoundException>(exception);
        }