(analytics beta) How to initialize Generic Dictionary from JS?

Here’s the sample c# code provided by Unity for the registration of a custom Analytics event:

  using System.Collections.Generic;
  using UnityEngine.Cloud.Analytics;

  int totalPotions = 5;
  int totalCoins = 100;
  UnityAnalytics.CustomEvent("gameOver", new Dictionary<string, object>
  {
    { "potions", totalPotions },
    { "coins", totalCoins }
  });

I have attempted to convert this to JS, but met with limited success:

import System.Collections.Generic;
import UnityEngine.Cloud.Analytics;

UnityAnalytics.CustomEvent("gameOver", new System.Collections.Generic.Dictionary.<System.String, System.Object> ({
		"name": screenName,
		"coins", totalCoins
	}));

Above code results in the following error:

Assets/Worlds/_Index/Scripts/IndexContentScreens.js(110,96): BCE0004: Ambiguous reference 'constructor': System.Collections.Generic.Dictionary.<String, Object>.constructor(System.Collections.Generic.IDictionary.<String, Object>), System.Collections.Generic.Dictionary.<String, Object>.constructor(System.Collections.Generic.IEqualityComparer.<String>).

Anyone care to point me in the right direction?

@Aubrey is right,
You can do something like this in Javascript:

var params = new System.Collections.Generic.Dictionary.<System.String, System.Object>();
  params.Add("coins", 2);
  params.Add("armor", "Shield");
  UnityAnalytics.CustomEvent("MyCustomEvent",params);