title: How do I get the instance value of a property marked with a Attribute?
body: <p>I have a class which is marked with a custom attribute, like this:</p>
  
  <pre><code>public class OrderLine : Entity
  {
      ...
      [Parent]
      public Order Order { get; set; }
      public Address ShippingAddress{ get; set; }
      ...
  }
  </code></pre>
  
  <p>I want to write a generic method, where I need to get the Property on a Entity which is marked with the  Parent attribute.</p>
  
  <p>Here is my Attribute:</p>
  
  <pre><code>[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
  public class ParentAttribute : Attribute
  {
  }
  </code></pre>
  
  <p>How do I write this?</p>