title: FluentValidation multiple validators
body: <p>Can I add more than one validator to an object? For example:
  </p>
  
  <pre><code>public interface IFoo
  {
      int Id { get; set; }
      string Name { get; set; }
  }
  
  public interface IBar
  {
      string Stuff { get; set; }
  }
  
  public class FooValidator : AbstractValidator&lt;IFoo&gt;
  {
      public FooValidator ()
      {
          RuleFor(x =&gt; x.Id).NotEmpty().GreaterThan(0);
      }
  }
  
  public class BarValidator : AbstractValidator&lt;IBar&gt;
  {
      public BarValidator()
      {
          RuleFor(x =&gt; x.Stuff).Length(5, 30);
      }
  }
  
  public class FooBar : IFoo, IBar
  {
      public int Id { get; set; }
      public string Name { get; set; }
      public string Stuff { get; set; }
  }
  
  public class FooBarValidator : AbstractValidator&lt;FooBar&gt;
  {
      public FooBarValidator()
      {
          RuleFor(x =&gt; x)
              .SetValidator(new FooValidator())
              .SetValidator(new BarValidator());
      }
  }
  </code></pre>
  
  <p>Running the test.</p>
  
  <pre><code>FooBarValidator validator = new FooBarValidator();
  validator.ShouldHaveValidationErrorFor(x =&gt; x.Id, 0);
  </code></pre>
  
  <p>I get an <code>InvalidOperationException</code>:</p>
  
  <blockquote>
    <p>Property name could not be automatically determined for expression x => x. Please specify either a custom property name by calling 'WithName'.</p>
  </blockquote>
  
  <p>Is there any way to implement this or am I trying to use FluentValidation in a way that it's not meant to be used?</p>