title: Checking existence of lazy loaded child without getting/loading in Fluent NHibernate
body: <p>This should be easy, but I can't seem to figure it out... How can I check if a child on an entity exists without actually getting or fetching it?  The child is lazy loaded right now..</p>
  
  <p>so I have two entities:</p>
  
  <pre><code>class A
  {
      public virtual int Id { get; set; }
      public virtual B Child { get; set; }
  }
  class B
  {
      public virtual int Id { get; set; }
      public virtual byte[] Blob { get; set; }
  }
  </code></pre>
  
  <p>I want to check for existence of B in an instance of A without actually fetching the large blog...  In straight sql I could just check to see if child_id is not null... Is there some way I can query the NHibernate Proxy of B in A?</p>
  
  <p>Thanks! </p>