title: How add data in nested relation? I have" Must be non-negative and less than the size of the collection" error
body: <p>I want to add data in relational model</p>
  <pre><code>public class person
  {
      public int id {get;set;}
      public string name {get;set;}
      public virtual ICollection&lt;phone&gt; Phones {get;set;}
  }
  
  public class Phone{
      public int id {get;set;}
      public string Phonenumber {get;set;}
      public int personid {get;set;}
      public virtual person Person {get;set;}             
      public virtual ICollection&lt;phone&gt; Phones {get;set;}
      
      public virtual ICollection&lt;Address&gt; Addresses {get;set;}
  }
  
  public class Address{
      public int id {get;set;}
      public string desc {get;set;}
  }
  </code></pre>
  <p>when i fill</p>
  <pre><code>person.Phones[0].Addresses[0].desc= &quot;1&quot;;
  </code></pre>
  <p>I have this error:</p>
  <p>How do I resolve index was out of range. Must be non-negative and less than the size of the collection</p>