title: How to store nested objects in different mongodb collection?
body: <p>I need to store some objects of this classes:</p>
  
  <pre><code>public class Category{
      public ObjectId Id {get;set;}
      public string Name {get;set;}
      public string Description {get;set;}
      public List&lt;Product&gt; Products {get;set;}
  }
  
  public class Product{
      public ObjectId Id {get;set;}
      public string Name {get;set;}
      public string Description {get;set;}
      public decimal Price {get;set;}
  }
  </code></pre>
  
  <p>When I use NoRM and store a Category object with 
  mongo.GetCollection().Insert(Category);
  I can see in mongo shell:</p>
  
  <pre><code>db.Category.find()
  { "_id" : ObjectId("82bbbf0179eae0141d020000"), "Name" : "Test products", "Descr
  iption" : "This is test category", "Products" : [
          {
                  "_id" : ObjectId("81bbbf0179eae0141d000000"),
                  "Name" : "Product1",
                  "Description" : "first product",
                  "Price" : {
  
                  }
          },
          {
                  "_id" : ObjectId("82bbbf0179eae0141d010000"),
                  "Name" : "Product2",
                  "Description" : "second product",
                  "Price" : {
  
                  }
          }
  ] }
  </code></pre>
  
  <p>Can I store Category and Product objects in different collections and have just a reference to a Product within a Category record without changing the code of classes? (The way like NHibernate does)</p>