title: How can I map two columns to one member using Fluent NHibernate and IUserType?
body: <p>I have an IUserType which maps two columns into a single type like this:</p>
  
  <pre><code>....
  public object NullSafeGet(IDataReader rs, string[] names, object owner)
  {
      return new FooBar(rs[names[0]], rs[names[1]]);
  }
  ....
  </code></pre>
  
  <p>I'm having trouble specifying the two column names using Fluent NHibernate. I've tried this:</p>
  
  <pre><code>Map(x =&gt; x.Boz).Columns.Add("GLUB","SHERP").CustomType&lt;FooBarUserType&gt;();
  </code></pre>
  
  <p>But the second column name is ignored. How can I specify the two column names using Fluent NHibernate?</p>