only null values </li>    <li>Sequences of perfectly normal values :) </li>    <li>Projections for all the above </li>    <li>A sequence with just over int.MaxValue elements, to test we can count properly </li> </ul>  <p>Then I have a few extra tests for interesting situations. First I check the overflow behaviour of each type, using a common pattern of averaging a sequence of (max, max, -max, -max) where &quot;max&quot; is the maximum value for the sequence type. The results are:</p>  <ul>   <li>For int we