public void TestRemoveNode()
{
Node testNode = new Node();
testNode.Id = -1;
testNode.Latitude = 0;
testNode.Longitude = 0;
var source = new MemoryDataSource();
source.AddNode(testNode);
// test if the node is actually there.
Assert.AreEqual(testNode, source.GetNode(-1));
// remove the node.
source.RemoveNode(-1);
// test if the node is actually gone.
Assert.IsNull(source.GetNode(-1));
}