public void AverageDistance()
{
Assert.AreEqual(0, instance.AverageDistance);
instance.Add(new MessageItem(new UserItem(new TweetUser()), new TweetData {
Tick = 1, Latitude = 48.237867, Longitude = 16.389477
}));
Assert.AreEqual(0, instance.AverageDistance);
instance.Add(
new MessageItem(
new UserItem(new TweetUser()),
new TweetData()
{
Tick = 2,
Latitude = 48.672309,
Longitude = 15.695585
}));
Assert.AreEqual(35215.795759484099d, instance.AverageDistance);
}