title: How to serialize class in custom library
body: <p>I have a class in my C# library:</p>
  
  <pre><code>public class PositiveLayer : MonoBehaviour
  {
      [SerializableField]
      internal BezierPoint[] Bezier { get; private set; }
  
      public PositiveLayer()
      {
          Bezier = new BezierPoint[0];
      }
  
      [Serializable]
      public class BezierPoint
      {
          public Vector2 Target;
          public Vector2 Tangent;
      }
  }
  </code></pre>
  
  <p>The Unity3D can see this class in my library and allows to add like a component to a some <code>GameObject</code> in the scene. But it lost a state in prefabs. How to provide serialization for classes inside C# library (.DLL)?<br>
  How should I change these classes to the Unity3D's editor could make a correct prefab to save this script state? Is it possible if my class locates inside <code>.dll</code> library? If it isn't, how can I separate it in inner and outter realizations to it was possible?</p>