title: How to call DynamicObject.TryGetMember directly?
body: <p>I'm implementing a general purpose function to extract a value from an arbitrary provided dynamic object, but don't know how to call <code>TryGetMember</code> because it requires a <code>GetMemberBinder</code> which is abstract, hence I cannot create it.
  Sample...</p>
  
  <pre><code>public object GetValue(DynamicObject Source, string FieldName)
  {
      object Result = null;
      GetMemberBinder Binder = x;  // What object must be provided?
      Binder.Name = FieldName;
      if (Source.TryGetMember(Binder, out Result))
         return Result;
  
      throw new Exception("The field '" + FieldName + "' not exists");
  }
  </code></pre>
  
  <p>Is there an already existent concrete descendant of GetMemberBinder ready for use? or a guideline to create my own implementation?</p>