; <span class="Keyword">this</span> IEnumerable&lt;TSource&gt; source,     <br />&#160;&#160;&#160; Func&lt;TSource, <span class="ValueType">bool</span>&gt; predicate)     <br />{     <br />&#160;&#160;&#160; <span class="Statement">if</span> (source == <span class="Keyword">null</span>)     <br />&#160;&#160;&#160; {     <br />&#160;&#160;&#160;&#160;&#160;&#160;&#160; <span class="Statement">throw</span>&#160;<span class="Keyword">new</span> ArgumentNullException(<span class="String">&quot;source&quot;</s