public void Can_get_all_elements_directly_connecting_two_nodes()
{
IList <IFiniteElement> results = SUT.GetAllElementsDirectlyConnecting(node1, node2);
Assert.IsNotNull(results);
Assert.AreEqual(1, results.Count);
Assert.IsTrue(results.Contains(spring1));
results = SUT.GetAllElementsDirectlyConnecting(node2, node3);
Assert.IsNotNull(results);
Assert.AreEqual(1, results.Count);
Assert.IsTrue(results.Contains(spring2));
}