VibeD - undefinded identifier

[holo via Digitalmars-d-learn]

Hello

Im trying to create REST api for my simple web page. My code is 
looking like below:

module service.frontpage;

import vibe.d;

@path("/api")
interface IFrontPageAPI
{
   Json getHome();
}

class FrontPageAPI : IFrontPageAPI
{


   this(auto tmp)
   {
     auto collect = tmp;
   }

   Json getHome()
   {
     logInfo("Getting HomePage from DB");
     Bson query = Bson(["_id" : Bson("homepage")]);
     auto result = collect.find(query);


     logInfo("Iterating results...");
     foreach (i, doc; result.byPair)
     logInfo("Item %d: %s", i, doc.toJson().toString());

     return result.toJson();
   }
}

But when i try to compile it im getting:

source/service/frontpage.d(15,3): Error: undefined identifier 
'tmp', did you mean alias 'cmp'?

Did i miss something?