public void RegisterRemoveEvent()
{
string testData1 = "TestData1";
string testData2 = "TestData2";
var go = new GameObject {
Data = testData1
};
EntityRef <GameObject> testRef = pool.Create(go);
string test = testData1;
testRef.RegisterRemovedCallback((go) => test = testData2);
pool.Remove(testRef);
Assert.AreEqual(testData2, test);
}