title: Fluent Validation Handle Exception
body: <p>I have some custom rules defined in an AbstractValidator class and I want that when there is an internal exception (e.g. NullReferenceException) in the rule definition, the validation process to return this in <strong>Errors</strong> collection. Now, when encounters an exception, the validation stops and that exception is thrown.</p>
  <pre><code> RuleFor(order =&gt; order.Products).Must(products =&gt;
  {
      HashSet&lt;string&gt; domains = products
          .SelectMany(product =&gt; product.Stock.Domains)
          .Select(domain =&gt; domain.Name)
          .ToHashSet();
  
      return domains.Count &gt;= distinctDomains;
  }).When(order =&gt; order.Products.Count &gt;= maxProductsCount)
  </code></pre>
  <p>E.g. When <em>Domains</em> property is null, an exception is thrown and the validation stops. I want the validation process to continue, and to append somehow what happened in <strong>Errors</strong> collection (from ValidationException).</p>
  <p>Are there any options to obtain such a behavior?</p>