public IEnumerator ElementReplacement()
{
// setup the layers
MemoryLayer upperLayer = MockLayer(new Vector3(50, 0, 50));
MemoryLayer lowerLayer = MockLayer(new Vector3(0, 0, 50));
// release for a frame so that start can be called on the layers
yield return(null);
// associate the layers with eachother
upperLayer.layerBelow = lowerLayer;
lowerLayer.layerAbove = upperLayer;
// set the layer latencies to 1 which will make the packets arrive in a single update
upperLayer.layerLatency = 1;
lowerLayer.layerLatency = 1;
// add addresses to the upper layer
upperLayer.AddMemoryLocation(0);
upperLayer.AddMemoryLocation(1);
upperLayer.AddMemoryLocation(2);
upperLayer.AddMemoryLocation(3);
upperLayer.AddMemoryLocation(4);
// set the size of the lower layer to 3
lowerLayer.SetSize(3);
// make three calls to fill the lower layer
lowerLayer.MakeRequest(0);
lowerLayer.MakeRequest(1);
lowerLayer.MakeRequest(2);
// wait for the requests to be handled
yield return(new WaitForSeconds(1));
// make a new request which should cause a replacement
lowerLayer.MakeRequest(3);
// wait for the request to be handled
yield return(new WaitForSeconds(1));
// the lower layer should now contain the most recently requseted address
Assert.IsTrue(lowerLayer.CheckForAddress(3) >= 0);
// it should also only contain three elements
Assert.IsTrue(3 == lowerLayer.memoryLocations.Count);
}