public void TestEquals()
 {
     var other = new BsonDocument("x", 1);
     var wrapper = new BsonDocumentWrapper(new BsonDocument("x", 1));
     Assert.AreEqual(false, wrapper.IsMaterialized);
     var result = wrapper.Equals(other);
     Assert.AreEqual(true, wrapper.IsMaterialized);
     Assert.AreEqual(true, result);
 }