anchor.diff:  === user.join.response
   
   === user.joined
  -[source,json]
  +[source]
   {
       "id": "7686d130-2223-4769-ab9f-5cebcf795e80"
   }
  
positive.code: === group.poker.start.response
  
  === group.poker.bet.request
  [source,json]
  {
      "id": "7686d130-2223-4769-ab9f-5cebcf795e80",
      "bet": 13 // allowed values: -1, 0.5, 1, 2, 3, 5, 8, 13, 20, 30, 40, 100
  
negative.code: === user.leave.response
  
  === user.left
  [source]
  {
      "id": "7686d130-2223-4769-ab9f-5cebcf795e80"
  }
  
  === group.create.request
  [source]
  {
      "name": "my group name", // min. 3 characters; max. 64 characters;
      "password": "secret" // min. 8 characters
  }
  
  === group.create.response
  [source]
  {
      "id": "7686d130-2223-4769-ab9f-5cebcf795e80"
  }
  
  === group.created
  [source]
  {
      "id": "7686d130-2223-4769-ab9f-5cebcf795e80"
      "name": "my group nyme"
  