@Test
 public void shouldThrowExceptionIfNoProgramProductExistForGivenProgramIdAndProductId() {
   when(programProductMapper.getIdByProgramAndProductId(1L, 2L)).thenReturn(null);
   expectedEx.expect(DataException.class);
   expectedEx.expectMessage("programProduct.product.program.invalid");
   programProductRepository.getIdByProgramIdAndProductId(1L, 2L);
 }
  @Test
  public void shouldGetProgramProductIdByProgramAndProductId() {
    when(programProductMapper.getIdByProgramAndProductId(1L, 2L)).thenReturn(3L);

    assertThat(programProductRepository.getIdByProgramIdAndProductId(1L, 2L), is(3L));
    verify(programProductMapper).getIdByProgramAndProductId(1L, 2L);
  }