Mashup two Keen IO queries using Keen IO JS library v3

gistfile1.js

Keen.ready(function(){
  
  // ----------------------------------------
  // Total Session Count
  // How it works: 
  // Given a timeframe, calculate the number of unique session IDs found in the collection "screen_view"
  // We use the "screen_view" collection because we know there is at least 1 screenview for every session.
  // ----------------------------------------
  var sessions_count = new Keen.Query("count_unique", {
    eventCollection: "screen_view",
    targetProperty: "session.id",
    timeframe: timeframe,
    timezone: timezone
  });

  // ----------------------------------------
  // Total Paid Session Count
  // How it works: 
  // Given a timeframe, calculate the number of unique session IDs that are found in the collection of payment events
  // ----------------------------------------
  var paid_sessions_count = new Keen.Query("count_unique", {
    eventCollection: "payment",
    targetProperty: "session.id",
    timeframe: timeframe,
    timezone: timezone
  });

  var mashup = client.run([sessions_count, paid_sessions_count], function(res){  // Send query to Keen IO
	$('#total-session-count').html(this.data[0].result)  // Print the query result to appropriate div
	$('#paid-session-count').html(this.data[1].result)  // Print the query result to appropriate div
	
	// divide paid sessions by sessions to get conversion rate
	var conversion_rate = (this.data[1].result/this.data[0].result).toFixed(2)*100
	
  	window.chart = new Keen.Visualization({result: conversion_rate}, document.getElementById('paid-session-conversion'), {
       	  chartType: 'metric',
       	  title: "Conversion %",
       	  width: 400,
       	  colors: ['#6ab975']
     	});
	
	// Or simply pass the value into a div 
	// $('#paid-session-conversion').html(conversion_rate)
  });

});