private EntityTreeNode mockOperationComponent(
      final Long id,
      final String nodeNumber,
      final Collection<Entity> inputProducts,
      final Collection<Entity> outputProducts,
      final List<EntityTreeNode> subOperations) {
    EntityTreeNode operationComponent = mock(EntityTreeNode.class);

    given(operationComponent.getId()).willReturn(id);

    EntityList inputProductsList = mockProductComponentsList(inputProducts);
    given(operationComponent.getHasManyField(OPERATION_PRODUCT_IN_COMPONENTS))
        .willReturn(inputProductsList);
    given(operationComponent.getField(OPERATION_PRODUCT_IN_COMPONENTS))
        .willReturn(inputProductsList);

    EntityList outputProductsList = mockProductComponentsList(outputProducts);
    given(operationComponent.getHasManyField(OPERATION_PRODUCT_OUT_COMPONENTS))
        .willReturn(outputProductsList);
    given(operationComponent.getField(OPERATION_PRODUCT_OUT_COMPONENTS))
        .willReturn(outputProductsList);

    given(operationComponent.getField(NODE_NUMBER)).willReturn(nodeNumber);
    given(operationComponent.getStringField(NODE_NUMBER)).willReturn(nodeNumber);

    given(operationComponent.getChildren()).willReturn(subOperations);

    return operationComponent;
  }
  @Test
  public final void shouldReturnNotEmptyMapIfManyParentOpConsumesManyOutputsFromOneSubOp() {
    // given
    Entity product1 = mockProductComponent(1L);
    Entity product2 = mockProductComponent(2L);
    Entity product3 = mockProductComponent(3L);
    Entity product4 = mockProductComponent(4L);
    Entity product5 = mockProductComponent(5L);
    Entity product6 = mockProductComponent(6L);
    Entity product7 = mockProductComponent(7L);
    Entity product8 = mockProductComponent(8L);
    Entity product9 = mockProductComponent(9L);
    Entity product10 = mockProductComponent(10L);
    Entity product11 = mockProductComponent(11L);
    Entity product12 = mockProductComponent(12L);

    EntityTreeNode node1A3 =
        mockOperationComponent(
            "1.A.3.", newArrayList(product11, product12), newArrayList(product10));
    EntityTreeNode node1A2 =
        mockOperationComponent(
            "1.A.2.",
            newArrayList(product10),
            newArrayList(product7, product8, product9),
            newArrayList(node1A3));
    EntityTreeNode node1A1 =
        mockOperationComponent(
            "1.A.1.",
            newArrayList(product7, product8, product9),
            newArrayList(product2, product3),
            newArrayList(node1A2));
    EntityTreeNode node1B1 =
        mockOperationComponent("1.B.1.", newArrayList(product6), newArrayList(product4, product5));
    EntityTreeNode node1 =
        mockOperationComponent(
            "1.",
            newArrayList(product2, product3, product4, product5),
            newArrayList(product1),
            newArrayList(node1A1, node1B1));

    given(tree.getRoot()).willReturn(node1);

    // when
    resultMap = technologyTreeValidationService.checkConsumingManyProductsFromOneSubOp(tree);

    // then
    assertNotNull(resultMap);
    assertFalse(resultMap.isEmpty());
    assertEquals(2, resultMap.size());
    assertEquals(2, resultMap.get(node1.getStringField(NODE_NUMBER)).size());
    hasNodeNumbersFor(node1, node1A1);
    hasNodeNumbersFor(node1, node1B1);
    hasNodeNumbersFor(node1A1, node1A2);
  }