title: Nhibernate QueryOver helper for date range without passing field name
body: <p>I have custom DateRange class and want to simplify adding new critera for QueryOver, by creating new helper method and passing lambda which contains the field I need and a date range. But I can't understand how to transfer and transform expression.</p>
  <pre><code>public static IQueryOver&lt;tRoot, tSubType&gt; AddDateRangeCritery&lt;tRoot,tSubType&gt;(this IQueryOver&lt;tRoot, tSubType&gt; query,
                           System.Linq.Expressions.Expression&lt;Func&lt;tSubType, object&gt;&gt; expr, DatesRange range)
      {
          if (range?.minDate != null)
              query.Where(??? &gt;= range.minDate.Value);
      }
  </code></pre>
  <p>I tried compile expression, but I feel it's not best idea + can't understand how to get passed to expression params. Is it possible to make this without ICriterion? Don't want to go this way because we can pass property and not field name, which more stable design.</p>