public void GetUnitById_ShouldReturn_NotNull()
        {
            // Arrange
            fakeUnitsRepository.Setup(a => a.GetById(1)).Returns(new UnitsModel());
            unitsService = new UnitsService(fakeUnitsRepository.Object);

            UnitsDtoModel unitDto = null;

            try
            {
                // Act
                unitDto = unitsService.GetUnitById(1);
            }
            catch (Exception ex)
            {
                errorMessage = ex.Message + " | " + ex.StackTrace;
            }

            // Assert
            Assert.IsNotNull(unitDto, errorMessage);
        }