public void GetNodeByTag_Should_Retrieve_Node_By_Tag() {
var tracker = new NodeTracker();
var node1 = new GraphNode("name1") {Tag = 1};
var node2 = new GraphNode("name2") {Tag = 2};
tracker.AddNode(node1);
tracker.AddNode(node2);
Assert.AreEqual(tracker.Nodes.Count(), 2);
Assert.AreSame(tracker.GetNodeByTag(1), node1);
Assert.AreSame(tracker.GetNodeByTag(2), node2);
}
public void GetNodeByTag_With_Invalid_Tag_Should_Return_Null() {
var tracker = new NodeTracker();
var node1 = new GraphNode("name1") { Tag = 1 };
tracker.AddNode(node1);
Assert.AreEqual(tracker.Nodes.Count(), 1);
Assert.IsNull(tracker.GetNodeByTag(2));
}