title: Fixing 'obsolete' warning when using MsgPack.Cli
body: <p>I'm using MsgPack.Cli to write a custom serializer for a Session class I have created. After creating the class using <a href="https://github.com/msgpack/msgpack-cli/blob/master/samples/Samples/Sample04_CustomSerializer.cs" rel="nofollow noreferrer">this tutorial on the MsgPack.Cli github page</a>, I receive this warning:</p>
  
  <blockquote>
    <p>Warning: 'MessagePackSerializer.MessagePackSerializer()' is obsolete: 'Use MessagePackSerializer(SerializationContext) instead.'</p>
  </blockquote>
  
  <p>I cannot work out what change would fix this warning. I don't think knowledge of MessagePackSerializer is necessary to help me with this; I simply do not understand the syntax of the warning.</p>
  
  <p>My code is included below:</p>
  
  <pre><code>namespace Something_Networky
  {
      public class Session
      {
          private int _n;
          public int n { get; }
  
          public Session(int n)
          {
              this._n = n;
          }
      }
  
      public class SessionSerializer : MessagePackSerializer&lt;Session&gt;
      {
          public SessionSerializer() : this(SerializationContext.Default) { }
  
          public SessionSerializer(SerializationContext context) // Warning displayed on this line
          {
  
          }
  
          protected override void PackToCore(Packer packer, Session value)
          {
              throw new NotImplementedException();
          }
  
          protected override Session UnpackFromCore(Unpacker unpacker)
          {
              throw new NotImplementedException();
          }
      }
  }
  </code></pre>
  
  <p>Thanks for your help.</p>