def test_delete_object():
    element_father = ProjectObject(81818, "Testing1", "2015-07-31", 60, 100, 40)
    element_child = ProjectObject(81820, "Testing2", "2015-07-31", 10, 30, 20)
    element_child1 = ProjectObject(81821, "Testing3", "2015-07-31", 30, 40, 10)

    element_father.add_list_child(element_child)
    element_child.add_list_child(element_child1)

    response = element_father.delete_object()

    assert len(element_father.children) == 0
    assert len(element_child.children) == 0
    assert response == [81818, 81820, 81821]
def test_delete_object1():
    element_father = ProjectObject(81818, "Testing1", "2015-07-31", 60, 100, 40)
    element_child = ProjectObject(81820, "Testing2", "2015-07-31", 10, 30, 20)
    element_child1 = ProjectObject(81821, "Testing3", "2015-07-31", 30, 40, 10)
    element_child2 = ProjectObject(81822, "Testing4", "2015-07-31", 30, 40, 10)

    element_father.add_list_child(element_child)
    element_child.add_list_child(element_child1)
    element_child1.add_list_child(element_child2)

    response = element_child1.delete_object()

    assert len(element_father.children) == 1
    assert element_father.children[0].element == element_child.element
    assert len(element_child.children) == 0
    assert element_child1.parent == ""
    assert response == [81821, 81822]