public async Task EditEmployeeHours_WhenNotExists()
        {
            await dbContext.EmployeeHoursCollection.AddAsync(
                new EmployeeHours { EmployeeHoursId = 101, Value = 100f, TimePeriod = "02.01.2019_08.01.2019", EmployeeId = 4 });

            await dbContext.EmployeeHoursCollection.AddAsync(
                new EmployeeHours { EmployeeHoursId = 102, Value = 100f, TimePeriod = "02.01.2019_08.01.2019", EmployeeId = 4 });

            await dbContext.SaveChangesAsync();

            var dao   = new PostgresDataAccessObjectService(dbContext);
            var newEH = new EmployeeHours {
                EmployeeHoursId = 666, Value = 100f, TimePeriod = "02.01.2019_08.01.2019", EmployeeId = 4
            };

            bool exThrown = false;

            try {
                exThrown = true;
                dao.EditEmployeeHours(newEH);
            } catch (Exception e) {
                Assert.Equal(typeof(InvalidOperationException), e.GetType());
                Assert.Equal("EmployeeHours object not found", e.Message);
            }
            Assert.True(exThrown);
        }
        public async Task EditEmployeeHours_WhenExists()
        {
            await dbContext.Employees.AddAsync(new Employee { Name = "Ola AAA", Email = "*****@*****.**", EmployeeId = 4 });

            await dbContext.EmployeeHoursCollection.AddAsync(
                new EmployeeHours { EmployeeHoursId = 101, Value = 100f, TimePeriod = "02.01.2019_08.01.2019", EmployeeId = 4 });

            await dbContext.EmployeeHoursCollection.AddAsync(
                new EmployeeHours { EmployeeHoursId = 102, Value = 100f, TimePeriod = "02.01.2019_08.01.2019", EmployeeId = 4 });

            await dbContext.SaveChangesAsync();

            var dao = new PostgresDataAccessObjectService(dbContext);

            var newEH = new EmployeeHours {
                EmployeeHoursId = 101, Value = 777f, TimePeriod = "02.01.2019_08.01.2022", EmployeeId = 4
            };

            dao.EditEmployeeHours(newEH);
            var obj = dao.GetOneEmployeeHours(101);

            Assert.NotNull(obj);
            Assert.Equal(101, obj.EmployeeHoursId);
            Assert.Equal(777f, obj.Value);
            Assert.Equal("02.01.2019_08.01.2022", obj.TimePeriod);
            Assert.Equal(4, obj.EmployeeId);
        }