public void GraphIdAndHashCodeTest()
{
var graph1 = new PropertyGraph(123, null) { Description = "The first graph." };
var graph2 = new PropertyGraph(256, null) { Description = "The second graph." };
var graph3 = new PropertyGraph(123, null) { Description = "The third graph." };
Assert.IsNotNull(graph1.Id);
Assert.IsNotNull(graph2.Id);
Assert.IsNotNull(graph3.Id);
Assert.IsNotNull(graph1.Description);
Assert.IsNotNull(graph2.Description);
Assert.IsNotNull(graph3.Description);
Assert.IsNotNull(graph1.GetHashCode());
Assert.IsNotNull(graph2.GetHashCode());
Assert.IsNotNull(graph3.GetHashCode());
Assert.AreEqual(graph1.Id, graph1.GetHashCode());
Assert.AreEqual(graph2.Id, graph2.GetHashCode());
Assert.AreEqual(graph3.Id, graph3.GetHashCode());
Assert.AreEqual(graph1.Id, graph3.Id);
Assert.AreEqual(graph1.GetHashCode(), graph3.GetHashCode());
Assert.AreNotEqual(graph1.Description, graph2.Description);
Assert.AreNotEqual(graph2.Description, graph3.Description);
Assert.AreNotEqual(graph3.Description, graph1.Description);
}