Check null value in a list using linq
<p>I have a list <code>List&lt;OfferComparison&gt; Comparison</code>. I want to 
check if all the items have <code>Value == null</code> in an <code>if</code> condition.</p>

<p>How can I do it with linq?</p>

<pre><code>public class OfferComparison : BaseModel
{
    public string Name { get; set; }
    public string Value { get; set; }
    public bool Valid { get; set; }
}
</code></pre>