<h3>Query expressions</h3>  <p>So far, we&#39;ve been calling the method directly (although as an extension method) - but LINQ also provides us with query expressions. Here&#39;s our &quot;SimpleFiltering&quot; test rewritten to use a query expression:</p>  <div class="code">[Test]    <br /><span class="Modifier">public</span>&#160;<span class="ValueType">void</span> QueryExpressionSimpleFiltering()     <br />{     <br />&#160;&#160;&#160; <span class="ValueType">int</span>[] source = { 1, 3, 4, 2, 8, 1 }; 