Changing elements order in query param Keys returns different results

#Given:

• URI1: http://ip:8092/test/_design/dev_catalog/_view/itemByCategory?keys=[%22Books%22%2C%22Games%22]&connection_timeout=60000&limit=1000&skip=0
• URI2: http://ip:8092/test/_design/dev_catalog/_view/itemByCategory?keys=[%22Games%22%2C%22Books%22]&connection_timeout=60000&limit=1000&skip=0
• Map function:
  function (doc) {
  if(doc.Type && doc.Type == "Application" && doc.Categories)
  {
  for(var item in doc.Categories.Category)
  {
  if(item == "CategoryName")
  Unknown macro: { emit(doc.Categories.Category[item], {"AppId":doc._id, "AppName":doc.ApplicationName}); }

  }
  }
  }

#When:
1. Call to URI1
2. Call to URI2

#Then:
1. With URI1 it returns elements which keys contains Books and Games.
2. With URI2 it returns elements which keys contains just Games only.

I think changing the elements order in the array should not modify the response.