void TestAnyNonZeroNeumannConditionsAndApplyNeumannToMeshBoundary()
    {
        // Load a 2D square mesh with 1 central non-boundary node
        TrianglesMeshReader<2,2> mesh_reader("mesh/test/data/square_4_elements");
        TetrahedralMesh<2,2> mesh;
        mesh.ConstructFromMeshReader(mesh_reader);

        BoundaryConditionsContainer<2,2,1> bcc;
        BoundaryConditionsContainer<2,2,2> bcc_2unknowns;

        TS_ASSERT_EQUALS(bcc.AnyNonZeroNeumannConditions(), false);

        bcc.DefineZeroNeumannOnMeshBoundary(&mesh);

        TetrahedralMesh<2,2>::BoundaryElementIterator iter;
        iter = mesh.GetBoundaryElementIteratorBegin();
        while (iter != mesh.GetBoundaryElementIteratorEnd())
        {
            TS_ASSERT(bcc.HasNeumannBoundaryCondition(*iter));
            double value = bcc.GetNeumannBCValue(*iter, (*iter)->GetNode(0)->GetPoint());
            TS_ASSERT_DELTA(value, 0.0, 1e-8);

            iter++;
        }
        TS_ASSERT_EQUALS(bcc.AnyNonZeroNeumannConditions(), false);

        iter = mesh.GetBoundaryElementIteratorBegin();

        ConstBoundaryCondition<2>* p_boundary_condition2 = new ConstBoundaryCondition<2>(-1);

        bcc_2unknowns.AddNeumannBoundaryCondition(*iter, p_boundary_condition2);
        TS_ASSERT_EQUALS(bcc_2unknowns.AnyNonZeroNeumannConditions(), true);
    }
    void TestAddNeumannBoundaryConditions()
    {
          // Load a 2D square mesh with 1 central non-boundary node
        TrianglesMeshReader<2,2> mesh_reader("mesh/test/data/square_4_elements");
        TetrahedralMesh<2,2> mesh;
        mesh.ConstructFromMeshReader(mesh_reader);

        BoundaryConditionsContainer<2,2,2> bcc;

        // No BCs yet, so shouldn't validate
        TS_ASSERT(!bcc.Validate(&mesh));

        // Add some BCs
        ConstBoundaryCondition<2> *bc1 = new ConstBoundaryCondition<2>(2.0);
        ConstBoundaryCondition<2> *bc2 = new ConstBoundaryCondition<2>(-3.0);

        TetrahedralMesh<2,2>::BoundaryElementIterator iter = mesh.GetBoundaryElementIteratorEnd();
        iter--;
        bcc.AddNeumannBoundaryCondition(*iter, bc1, 0);
        bcc.AddNeumannBoundaryCondition(*iter, bc2, 1);
        iter--;
        bcc.AddNeumannBoundaryCondition(*iter, bc1, 0);
        iter--;
        bcc.AddNeumannBoundaryCondition(*iter, bc2, 1);

        iter = mesh.GetBoundaryElementIteratorEnd();
        iter--;
        TS_ASSERT_DELTA(bcc.GetNeumannBCValue(*iter, ChastePoint<2>(), 0), 2.0, 1e-9);
        TS_ASSERT_DELTA(bcc.GetNeumannBCValue(*iter, ChastePoint<2>(), 1), -3.0, 1e-9);

        iter--;
        TS_ASSERT_DELTA(bcc.GetNeumannBCValue(*iter, ChastePoint<2>(), 0), 2.0, 1e-9);
        TS_ASSERT_DELTA(bcc.GetNeumannBCValue(*iter, ChastePoint<2>(), 1), 0.0, 1e-9);

        iter--;
        TS_ASSERT_DELTA(bcc.GetNeumannBCValue(*iter, ChastePoint<2>(), 0), 0.0, 1e-9);
        TS_ASSERT_DELTA(bcc.GetNeumannBCValue(*iter, ChastePoint<2>(), 1), -3.0, 1e-9);
    }