public void GetEmployee_idNotExist_return_null()
        {
            //Arrange
            int id = 5555;

            //Act
            A.CallTo(() => repo.GetEmployeeById(A <int> .Ignored)).Returns(null);
            var result = sut.GetEmployeeById(id);

            //Assert
            Assert.IsNull(result);
        }
 public Employee GetEmployeeById(int id)
 {
     return(repo.GetEmployeeById(id));
 }